Hi Ben, if I had a chance to do it over again, I would go to the track, find out what the top sponsored drivers are running and buy those cars (416x, cyclone, t3, BD5, TC5).
Reason:
1. Sponsored driver would usually help you get faster. They will usually share their setup (if you drive the same car).
2. Buying a mid level car might not be fast enough. Then upgrades. Then later give up and buy what the fast guys are running.
I would buy a second hand top rated car than a brand new mid level model. But if the joy is in building a brand new car, then that is a different matter.
Thanks.
Joel
P.S. Caveat, my 416WE is on the shelf and now drive a TL01 in the 13.5T class.