Here's my STL car on paper. Nothing crazy, mostly a b-series swap with the usual Honda bolt-ons. I'd expect a car like this to be competitive at the regional level. This could also be a NASA H2 car.
89-91 Honda CRX
B16A motor (stock internals)
DC Sports 4-2-1 header
AEM intake
LSD, (I'll have to do some research on the OEM final drives that fall within the rules)
Koni yellow/Ground Control coil over suspension (standard CRX road racing setup)
Min weight = 2080 lbs so, with a stripped chassis, I'd have to run some ballast.
There's still plenty of room for development (e.g., aero, ECU, engine work within the rules, better suspension, etc.) but I believe the above is very much the Honda "cheap and easy" button for this class.
I currently race an ITA/H4 CRX Si but would prefer to start with a clean chassis for this car if I actually build it. Lately, I find myself checking Craigslist for clean EF CRXes....