You see guys, I dont want to be spending like £160 on Guitar Hero: World Tour, its just like the same price as the 360 itself. Can you buy the guitar hero games with just a guitar with it?

I have guitar hero 2 and rock band, is it possible to play guitar hero 2 using both the guitar provided by guitar hero and the one provided by rock band?
If so, how?

I am planning on becoming really good at playing the guitar but i love playing guitar hero too…would that be weird if i was really good at the guitar and played guitar hero still?