Let's Make Robots!

RobotC Compatible Microcontrollers

I received a copy of RobotC and the USB/Serial interface with my VEX robot kit.
As I become acquainted with it, I realize that it could solve control of a model railroad cable car system that terminates inside a model building and must be left unattended on public display.  The ability to exercise fine control through reprogramming rather than physically rearranging parts would be a major plus.
However the VEX microcontroller is much too expensive and has far too many features for the simple sensing, timing, and current reversing features that I need.  Sensing can be by a pair of microswitches (one in line with each car) or by a single IR sensor across the paths of both cars.
Can anyone suggest microcontrollers that can accept RobotC firmware and programs through a USB cable or the USB/Serial cable that I have?