Front wishbones and front driveshafts (you can buy the dogbone on its own) maybe a spare spur gear and a set of gears is about it really other than maybe the front shock tower, unless you are using the thicker atomic carbon one
Also check the car to see if it has the tapered outdrive springs fitted between the driveshaft and the one way outdrive, this should stop the bending and breaking of the driveshafts but i have not fully tested them yet.
And set the slipper right as this will save the transmission if you are making big jumps etc.