and of course: tirerack.com
if you're doing open track events and not competing I would recommend you not go too crazy with semi-slicks etc. You'll improve quicker on a tyre that is more progressive at the limit, rather than a proper race tyre where the grip is more on/off. That way you can have a better feel for how the car reacts to different inputs. On race rubber its easy to make a bunch of small mistakes and not even be fully aware of it because the grip level is so high.
understeering? visit FealSuspension.com
for quality repairs and modifications in the LA area: StevesAutoClinic.com