You should be able to request your base, in order of your class seniority. If you're going to be flying the CRJ, hopefully you get based in ORD! Otherwise, if you're going to be in the Brasilia, it might be a long haul from anywhere I would say SFO would be best and seems to be easy to get to from the bottom of the seniority list, but LAX or SLC would probabably be great also since it's not a multi leg commute. Good luck!