+ 1 on those shocks you have because I built them
Regards to wheels on the x4 pro it comes with the driveshafts that are designed to take associated type wheels as dave uses. If you buy the mad rat /x2/x2-c wheels you will have to drill out the holes to fit them over the axles. This is the same with Kyosho wheels.
Oh and steer clear of fastrax spoke wheels as they break quite easily as Mr Petch found out. Plus the offset is huge.