Well I've read good reviews regarding the
FreshRoast SR500 Automatic Coffee Bean Roaster
but if you don't really want to spend that much many people seem to be having luck with roasting on a popcorn popper the Wabash popcorn popper.

If you wish to buy it you can do it from my affiliate links freshroast SR500 and Wabash popcorn popper

Hope it helps! feel free to ask for any more information if you need.