They can all be made to go fast. The KSG is a great car. Andy, took his ideas and designs from when he was with bolink and used them on his own cars when he started KSG. Its a flexy flyer for sure. The car has a strong back east following, but here out west, the Maverick cars and Hyperdrive are the the top dogs.
If your not totally stuck on KSG then I would take a look at Swift's Maverick and OPC oval cars. They rip. I ran the Maverick (slider car) on carpet, at the Birds, and for the rest of my season, which is outdoors, I run the OPC wich is the One Piece Chassis. It has a little more flex in the chassis, but overall is still a very stiff car. Your setup changes are much more apperent, and the chassis can be faster then a car with more flex in it.
You wont find any better CS with the swift cars out there and there are pleanty of fast guys running them to give you setups. I had a very fast car eirly on at the birds, but as the track went to crap, lost it, but can give you any info about seting up the cars.
check them out at www.JPHracing.com
you can e-mail jake with any more question about them.