Go to the place that offers you the job first. It is foolish to stand around waiting for your "dream" regional to call when you could be working/gaining experience/seniority. They are regional airlines and they all suck! If you started class today, you've still got a few years before you will max out at FO pay. A lot can happen in those years, bases, pay, aircraft, and schedules can all change. Good luck in your decision, I hope it works out for you.