Question about the 8300 (a.k.a. Curve)

Hey all,

Thank you firstly for taking the time to read this.
My question is such. I am 18 years old and am moving to college in southern California this fall. I currently have a regional carrier here in S.F. (MetroPCS) and am planning on switching to a main carrier.

My brother has Verizon, and my parents have Sprint, and they have asked me to join either network for a family plan, and I completely understand since they are already shelling out tens of thousands for my education next year. Also LMU (my college) has Verizon and Sprint towers on campus, so naturally they have the best reception.

The phone I am most interested in is the Blackberry 8300 (aka Curve), but it is only available through CIngular. Would it be possible to take an unlocked 8300 and insert a SIM Card from Sprint or Verizon and use it that way or would it be denied by these networks? And would the applications and internet capabilities be impacted? Would there be any way at all to use this phone on the networks of either of these carriers?

The two other phones I was considering were the Blackberry 8830 and the Motorola Q(the camera is kind of a big factor for me as a college student). Would you recommend Sprint or Verizon? Which phone should I go with? Would unlocking 8300 and using it be possible?

Thanks again for taking the time,
littlezeck a.k.a Andy