I was fortunate to go out in a new Corvette Grand Sport for a "Test Drive" article and I have to say that I was pleasantly surprised. It has a MUCH nicer interior (should come that way in ALL Corvettes) and with the automatic w/ paddle shifter, it was a nice car to drive through town and with 436HP on tap, it got the job done, too. It does have upgraded brakes, but is not quite a Z06. I drove a C6 Z06 and that is definitely a street legal race car, but not something I'd want to drive every day. The Grand Sport is a great "middle ground" Corvette. Of course, most don't have the money to spend $60-70k to get a car that does almost everything well and still gets good mileage on the hwy.
As for getting an S30 to be both, dealing with old technology and trying to get road noise levels down with the old school suspension is next to impossible. Like BRAAP said, put newer stuff on the S30 body. My buddy has an M3 we wants to put on a C6 chassis (with definite modification) and he's the same guy who just bought a new Ferrari 458 and says it's the best car he's ever driven and is tempted to gut it and put in a cage, so he can go hit the track with it! It's always a compromise, I'd say!