have been thinking about doing a similar project as well.
giving the Pro 3 a lower chassis which expands the whole length of the car. making adjustments to the suspension arms much more easier. for example: Tamiya and X-Ray. doing away with placing shims inside shocks.
think it would be easier to use plexy glass or sheets of plastic to produce a prototype chassis first (hopefully cheaper). i'm sure you can find it in any Home Depot or picture framing bussiness.
if you do find some carbon fibre sheets. becareful not to inhale the dust when your cutting.