I don't have quite so much to contribute yet, other than to say the box-stock setup isn't very good at all for racing. Softer springs, lower weight shock oils, and Pro-Line tires suited for track conditions are a huge step in the right direction.

You can get by on the stock servo. I thought I would have broke it by now but it is still working. By this point though I'm starting to recognize that a higher torque unit would be very desirable

Aluminum suspension mount is good for durability, but definitely pass on the aluminum hub carriers as you'll end up breaking ballstuds back there very frequently on a racetrack with sizable jumps.