From what I understand, everything everyone else is saying is correct. If you are invited to a PEPC and try to ask for a change of facility while you are there, you're done. BUT I have heard that people in your situation should go through with the PEPC, don't say anything about wanting to transfer, and then AFTER you get your TOL call and talk to your HR rep. He/She might be able to help you, and they won't pull you out of the process just for asking. I don't know if you'll get what you are looking for, but you never know.
My question is, you say that your husband is going to hopefully be stationed in San Diego, but what happens if he isn't? Where could he possibly be stationed? Arizona? Germany? I'm just wondering what you will do if he is stationed somewhere other than SoCal?
As for the living where you work thing...my husband is going to be driving at least 45 min to 2 hours to work, depending on where we live. Not for community safety reasons, but for cost of living reasons. It might be a sacrifice you have to make in order to provide the best life for your family. While it won't be easy, as everyone else is saying, get CPC and get out if you don't like the area. With all the hiring the FAA is doing, you'll have pretty ok seniority in just a few years (think mass retirements and LOTS of new hires).
Good Luck though...it's is a hard process and lots of people don't even get to where you are. Really think it through before you throw it away (which is what you will be doing if you ask for a transfer at the PEPC).