Kimbrough mid sized servo saver is a must. The ones that comes stock on the kit will strip out. Servo wise, you can get away with a Futaba 3003 with the ears cut and the servo taped down to the chassis deck. If you go with some mini servo, make sure its a metal gear servo and not one of the plastic ones.
Get the Mazda 6 body 150mm - just as in TC, the 6 body seems to give the right flow. If Trey is still using the 27MHz lap counting system, grab a Novak XXL 27MHz Rx - a lot more compact than your typical Rx. If you guys are using the new timing system that is not dependent on the MHz any more, then look for a HiTec Micro Rx - they used to sell them and they were compatible with most radio systems - VERY small and nice!
The Spy ESC is a good choice, but if you get further into it, look to snag an LRP Micro QC2 - VERY nice ESC and definitely will allow you to run stock to mod on those cars.
Tire wise, if I recall, there are some Trinity TRC tires that I had bought that worked nicely. I think they were pink fronts and rears, if I'm not mistaken.
For batteries, I had used Team Helotes -
http://www.teamhelotes.com/~main/catalog/c18_p1.html - back then they did not have 1400's, only 1100's and they were plenty! Those packs you could peak out, race and never have to change them up - of couse, that was Stock racing and not mod.
I also had the M18 Rear LINKAGE SET, 2.5 deg. toe-in set and the graphite chassis. But that chassis was not something I had seen - I think someone had made it.
Hope that helps ya!
PD2