[Jon Stratis]

I doubt you'll find an off-the-shelf conveyor that'll work... every conveyor system i've seen on a robot has been something the team has designed and built themselves.

Figure out the material you want to use on the conveyor (do some searching on here, there is plenty of discussion). Figure out what you want your rollers to be made of, how you're going to mount them, and how you're going to power them. Put it all together and you have a working conveyor!