Yeah, Mesa is hiring people with less than 500 hours total. Most likely these would be the people from MAPD that receive preferential hiring. As a former MAPD instructor and Mesa Airlines FO I can say that the above post is correct to a point.
When I was hired by the airline in '04 we had the choice between the CRJ and the EMB-145. I fully expected to get the CRJ out of PHL but was assigned to the EMB-145 out of CLT. I will say that I've heard many, many Mesa pilots complain about the aircraft they were assigned. Once Mesa makes their decision there's nothing you can do to change it.
Other airlines 'may' give you more leverage when it comes to choosing aircraft and domiciles. But, due to seniority in the +20 class I was like 2nd or 3rd from the bottom so I really had no power. Also, most airlines you'll find that 50-75% of the flight crews commute. I knew a FO that was commuting all the way from San Diego to CLT.