I gotta go with battle pope on this one.
This dsm sounds reeeeeeal risky. If you absolutely must buy a dsm, at least get an awd gsx/tsi. These cars have huge aftermarkets and potential, but reliability is always an issue with them.
Pope's honda idea isn't bad, either. they are a great car to begin with. HUGE, cheap after market, and great potential. Sure, you won't get quad digit horsepower numbers out of them, but with a few bolt ons (maybe even a turbo kit?) some beefier tires/brakes/suspension, shed have a helluva time on the track.
I'd also suggest a miata, but they are waaaay more expensive than hondas and don't have half the aftermarket that hondas have.
Anywho, kudos to you for having a daughter that's into cars! Hopefully I can raise my baby sis to be a gear head
Good luck!