macbook enough for iphone app development ?

I decided to try selling few shitty apps after having seen what crap people acutally buy, tho it seems I need a macbook to make those

I don't want to buy an iphone on top of it so is the emulator thingy enough for development ?

Oh, btw, are there MAJOR differences between iphones and ipod touches, in terms of being capable of testing apps ?

I've found some dirt cheap refurbished ones, might also buy some if they'll work out fine.