For Christmas, I gave myself a Mark III mini sumo kit from Junun.org. A nice kit but probably not for the beginner.
The board is compact and looks very flexible, since all 40 pins of th PIC 16F877 are brought out to a header. Make sure you have a small soldering tip! The soldering of the board went quickly. I have yet to test it.
The servos it shipped with were unmodified, so the next step was to modify them. For me, the servo modification didn't go so well. I saw the instruction, "Be careful not to drill out the threads" but then used a large drill bit to be SURE I could get my screwdriver in there and now the screw to attach the servo horn/wheel no longer fits. The second servo I sheared off the moulded axle when trying to remove the servo stop.
Live and learn! I had two other servos lying around and even though they were slightly different (JR Racing instead of Futaba) I was able to modify them without breaking anything.