I'd probably go, take a later date if offered. Don't burn bridges that you don't have to, especially if you don't have a date or even CJO from envoy.
I don't think AAG is going to be upset if you chose one WO over another.
Also... you'll likely be at a regional for only a very few short years, I don't think I'd take any delay in building 121 time just so you can fly one RJ over another.
Living in base is a worthwhile consideration though, but again the sooner you get to a major the sooner you get real QOL and money.