i say get the used t1i for 475 or whatever it was i initially posted and but an l lens. the differences between the t1i, the t2i and the t3i are minimal. just because there are newer versions doesn't mean you need the newest one especially when chances are you'll grow out of it and maybe look for a full frame camera later. No reason to spend 900 bucks when you can get pretty much the same thing for 475. I would invest more in the lens since these cameras were talking about are aps-c and not full frame (35mm) sensors. Your overall image is going to very greatly on the lens then between these 3 bodies.
here is some more info on that digital sensor sizes and what it means to you:
http://en.wikipedia.org/wiki/APS-C