hey, new york. welcome to the forums!
basically, yes, you can install any OS that's made for the 8700x devices. the branding, however, has more to do with the theme than the OS. there's oodles of information around the forum on these topics. look for sticky threads at the top of the thread lists.
it shouldn't be much hassle at all to launch with t-mo. you would be best, however, with a data plan. otherwise just pop your sim in and go.
curiously, why did you choose BB?
8300 Curve: viigo, gmail, google maps, way too many emails/day
Last edited by theBorg : 07-18-2007 at 02:48 PM.
Reason: Clarified OS compatibility per Perfect Storm's comment.