This might get long...
I got engaged May of my 1L year and got married August of my 2L year. I immediately ruled out 3L summer because I didn't want to be distracted with wedding stuff while I was studying for the bar, and I wanted time to go on a honeymoon. This left me winter break, spring break, summer before SA job, or summer after SA job of my 2L year.
I chose the end of my 2L summer -- this left me one week off after my job ended for last minute details and travel (my original flight was cancelled due to a storm -- in AUGUST -- so build in time just in case), a weekend for the wedding, one week for a honeymoon, and then classes started.
My second choice would have been 2L summer between exams ending and SA job starting, but you'll be pretty distracted so keep that in mind. I also have a classmate who just got married during spring break, but I enjoyed the time off before the wedding since I was getting married cross-country from where I go to law school and had last minute things to take care of. I have another classmate (a guy) getting married this summer while studying for the bar, and I think that's a bad idea. They are going on a honeymoon in November, and it's bound to be distracting. You'll either get distracted from your studying or be a miserable grouchy bride...
Even if you get married after the bar, you'll be distracted with last minute wedding stuff and why add one more thing to your plate?
FWIW, my firm had a 12 week summer program and it ended Aug 8 -- I got married the 17th, took an 8 day honeymoon, and had one day off before classes started.
If you have any questions send me a message -- and congrats!