Parallax sells these as a basic kit, which includes only the aluminum panels and motors/wheels.
The controller was a BS2 borrowed from my BoeBot, a pair of HB-25s and some sensors. The HB-25s were overkill, but it's what i had.
Right now, it's undergoing some major surgery. Motors that came with it, I find, are geared way too high for indoors. After one of them blew itself to bits, replacements are Pololu 37Dmm gearmotors that bolted right up to the stock plates. The original Banebot axle adapters are also pretty much stripped out, so some Pololu adapters and 90x10mm wheels are going in. For a motor controller, I'm pulling out the HB-25s for a possible bigger bot and using a dual MC33926. And finally on battery, pulled out the VEX 7.2v nimh and using a 12v 5Ah SLA that'll be tucked in back. Those omni wheels on its tail seem to steer better with some weight on them, so a good place for a big chunk of battery. Not decided yet on controller, either Arduino or Propeller. The rest of the parts should be in later this week, so the little guy should hopefully be a bit more reliable.