Guitar Hero 3 - where to buy with extra controller

Hello all,

I am trying to buy guitar hero 3 for ps3 but I want it with two controller so I can play multiplayer. does anyone know how I can get it with 2 controllers? Or how I can get an additional controller? Ebay seems to have different models of controller (usually quite expensive and I'm worried they wont actually work) but i'd like two official ones if at all possible. I'd rather not spend more than £80 on all of it.

Any advice would be much appreciated...I don;t understand why they have multiplayer if you cant buy it with two controllers!!