I think its a pretty cool idea
F. A. S. T. has a website.
the regs of both classes I looked thru are pretty rigid as to how stock your car is. IE No mandrel bent exhaust tubes, and all kinds of other stuff you wouldnt think theyd be looking for.
Id look to see where/if there are local races (and waht kind of turnout they are getting) and also consider what do you do when the org changes or goes belly up ? Do you still have the car built the way you really want ?