My robots tend to use either Peter Waller's custom controllers or Sozbots ones, but a good starter option (as I might have suggested earlier) is the Sabertooth 2x5A for RC - http://www.active-robots.com/products/m ... ails.shtml - I used one of these in my first ant with no problems. (it then went on a bit of a journey and presently resides in Andy Jackson's antweight :P)

That will give you skid steering with an option to either drive it tank style or have the control signals mixed so you can control it with one stick on the transmitter.