In case anyone is interested, this conversion plus a full laydown option for tamiya 2wd buggies, plus some other tamiya bits are on my Shapeways store
CTE RC
The parts being used here are the Layback transmission, which is basically a short laydown type, using the 27t tamiya idler instead a larger idler of the Laydown transmission. This keeps the cg low, but moves the motor 9mm rearward for more traction. All the parts you need are listed with links on the Shapeways product descriptions. You also needs some carbon parts from fibre lyte.
Feel free to ask questions. Sorry for the thread hijack Mark!