Banjo Tooie is very rare at least in PAL form so will cost alot when you find it
but yea the n64 is the best console in my opion i still got my one with 4 controlers and about 20 odd games but your best bet for games you want to play is to buy this adapter thing
PSX , N64 controller adapter for PC USB (not nessecerly from this shop just first one i clicked on) and then you can get emulators to play the ones you cant get hold of and still use the n64 controler