If you start from the RTR or original kit I have the following list that I am recommending to a friend:
Upgrades for the SC10 4x4 RTR
- FT Upgrade Kit ASC1174
- FT Aluminum Wheel Hexes ASC91171
- FT Rear Sway Bars ASC91124
- FT Front Sway Bars ASC91123
- AE 13mm Front Springs Yellow ASC91162 (use blue front in rear)
Clearly the Exotek chassis would be good but he is not racing and we are in Brazil so this is a little more of a stretch.