I attended SW as a PT student throughout my time there (Dec '06 grad). Because I always maxed out my units (11-12 per semester; 5-6 every summer), I was able to graduate after only 3.5 years, even though I was working full-time and commuting all the way from Ventura. So even if you stay PT, if you take enough units, you can graduate in about the same amount of time as the FT folks. Further, I had plenty of friends who started as PT, and were able to switch to FT after the first year.
I enjoyed my time at SW, and had no trouble passing the CA bar on the first attempt. So I think it's a great school. Enjoy it.
With respect to living arrangements, if you visit the school, they always have roomate ads up on the boards. I would try not to lock in long-term with someone you don't know very well. You may eventually meet people in class who would make a better roomates than your original cloice, and you want to maintain the option of exploring those opportunities within the first year.
So I've decided that I will be attending Southwestern Part-Time this fall. I really wanted full-time but after talking to admissions today they informed me that no decisions will me made until the very end of July/beginning of August and I just can't wait that long to find housing and move. Also there was no guarantee that I would be able to still have a part time spot if not offered a full time one. So I figured, why jeopordize an opportunity when I can just go part time and then transfer to full time next year. So now I have to find an apartment in LA! Anyone have any suggestions?