I get all Canon cameras because I've been really happy with the quality. That said I think Nikon is good quality too - once you get into the current SLRs you will have to say "I suck as a photographer" rather than "this camera sucks" if your pictures don't come out well. I would just pick the highest quality you can afford and then start saving for a new lens.

Maybe with the Nikon being cheaper you can get a new lens sooner? The lens can make all the difference. I got a higher end 28-135 lens so that I would have a nice range without needing multiple lenses. Photography can become an expensive hobby! I took a photography class too but I have yet to master anything so no more lenses for me til my skills warrant the equipment.