the pro4 is a good car. it's essentially the same as the evo3 surikarn. same sort of hopups, but better plastic quality in my opinion.
most people say "no options needed" but who really does that!
i've got the HPI carbon fibre driveshaft, it hasn't twisted with a hacker 6t, the square alloy camber mounts, hpi alloy servo mount.
the toe in blocks are essential. 1 degree through to 3.