I'd probably end up only playing guitar/bass (i heard you could play bass in Rock Band is it a seperate guitar or can you just play bass with the regular guitar?), maybe drums on an off occasion
singing is not an option
plus i don't have online right now
You actually might be better off with just going with Guitar Hero. You can play bass in both GH and RB using the regular guitar. There is no separate bass guitar you buy because, honestly, it'd be exactly like the regular guitar anyways, only bigger.