Completely agree with Groundhog about not putting to many eggs in one basket with this firm. It is very difficult for any firm to know what will happen in five years major clients could back out, another recession could occur, immigration reform could completely change how your firm operates etc.
If the firm was offering to pay for law school then the firm is putting it's money where it's mouth is, but of course they will tell any decent employee to stick around and pursue law school while working for them. You will be paying for own education making you more valuable while being paid the same rate. If you graduate, pass the bar, and it happens to be a good time I am sure they would hire you, but there is absolutely no guarantee that they will hold a position for you.
As to your overall question I always tell any incoming law student to consider the following factors in this order.
(3) Personal Feelings about school
(4) Understanding the reality of legal education
(5) Last and Least U.S. News Rankings.
This article does an excellent job analyzing these factors to any incoming law student. http://www.legalmatch.com/choose-the-right-law-school.html
, but I will analyze these factors to your current situation below.
I will also add some minor input about my thought on part-time law school, which I do not recommend, but to each their own. (1) Location:
For all intents and purposes San Diego and L.A. are pretty similar, but during law school you will not have the time or financial resources to go between the Cities. However, you will have time to enjoy life a little bit and for three years wherever you attend law school will be the City you spend 95% of your life in. Additionally, after three years it is unlikely you will move. If you stay in L.A. and work for that firm part-time there is a good chance you will end up at that firm or another L.A. firm. Additionally, you will make friends in San Diego or L.A. and likely enter into a serious romantic relationship or solidify an existing one during law school and that person will likely get a job in the City you attend law school. So upon graduation again you will likely stay in San Diego or L.A.
On top of that during law school you might find an apartment you love and don't want to leave for at least few years. These are all things that ended up happening to me and I still live 1 mile away from my law school, which is in a City I didn't intend to live in when I enrolled, but things happen and during your mid-late 20's you really solidify where you will end up living so if you really want to be in San Diego attend law school in San Diego. (2) Cost:
With your numbers I assume California Western would offer you a scholarship and if they haven't ask them to. However, be sure to negotiate your conditions and make sure they are fair. Many students get a 3.0 requirement and assume they will easily get that, but law school is a different animal with a steep curve and only about 35% of the 1L's can have a 3.0 and nothing personal, but there is a 65% chance you will not be in the top the 35%. 3) Personal Feelings about the school:
California Western and Loyola are fairly close to each other and I highly recommend you visit both schools. While there talk to professors, admins, walk around the neighborhood, check out the campus, and see, which one you like more. As a 0L I visited numerous law schools some I liked others I didn't, and whether you like something or not is a highly personal decision and the only way to answer it for yourself is to personally visit each school. After your visit you will likely have a gut feeling about both schools and listen to that feeling. (4) Reality of Legal Education:
At any ABA school you will receive a great legal education. Whether you attend California Western or Loyolya you will for all intents and purposes learn the same exact thing. Your first year will consist of Torts, Contracts, Civil Procedure, and Property. In these courses you will read Supreme Court cases and brief them. The Supreme Court does not write separate opinions for different schools and you will likely have the same exact textbooks for each of these courses at either school. At the end of three years you will sign up for the California BarBri or Kaplan Course and study for a** off for months then pack yourself into a room with thousands of other law school graduates wanting to be licensed to practice in California. If you pass that exam your an attorney if you don't your not regardless of what school you attend.
(5) U.S. News Rankings:
Remember this is nothing more than a for-profit magazine offering an opinion. U.S. News ranks everything form hospitals to best places to live. Albuquerque, New Mexico was ranked #1 place to live, but I imagine you will not make the life altering decision to move to New Mexico because U.S. News said it was #1. Here is the link showing New Mexico is #1 http://money.usnews.com/money/personal-finance/slideshows/best-places-to-live
Use the same logic when choosing your law school do not make a life altering decision based on what a magazine thinks. (6) Part time law school and your employer:
The majority of people that fail out of law school go part-time. The reason is that first year is insane no matter where you go, and if you are dealing with the struggles of work your academic performance will suffer. Even if you don't fail out there is no way to will be able to compete with students going full-time and your class rank will not be as good as it could be.
I personally feel if you making the $100,000 life altering decision to go to law school go "all-in" . Don't dip your toe in the water, because odds are you will not do well academically, you will not make connections in law school, and you will simply not have the same experience. There are people that can thrive in part-time programs, but the majority of people don't.
Again, as to your firm as I stated above there is no guarantee you they will hire you at graduation, but they might. However, a lot of doors will open once you are licensed to practice law unless this firm is where you want to work at graduation, which it might be don't settle. You are pursuing a J.D. to open doors don't put to much weight in this one firm if your not that into it. If it is a firm you want to work at and you are absolutely passionate about then perhaps part-time and working there is the best route, but only you can answer how interested you are in that firm. In closing don't sell yourself short and settle despite all the negativity from anonymous internet posters once you are licensed to practice law there are a lot of opportunities. Conclusion:
I am some random anonymous internet poster along with everyone else on this board or others so take my post and everyone other anonymous internet poster's advice with a major grain of salt. I have never met you, I know nothing about you, and I certainly do not know what is best for you and neither does any other anonymous internet poster.
What I do know is that either school will provide you with a solid education and an opportunity to be a licensed attorney. What you do with that license has far more to do with you than the school you attend and what the best decision for "you" is can only be answered by you. I encourage you to analyze the factors above to make your decision.
Good luck whatever you decide and congrats on your acceptances.