Cheap R compound tires ==
You might want to look at the Falken Azenis RT615 -- not R compound but cheap and sticky. Look at Discount Tire web site:
http://www.discounttire.com/dtcs/findTireProductCategoryDetailBrnd.do?rcz=85028&rc=AZRINT&tpc=FALHZA&tp=Passenger%2FPerformance&tc=FALHZA
The TOYO Proxes RA1 is a very good track tire and some of people drive them on the street. But, they are more expensive!
http://www.toyo.com/docs/tires/tires.asp?lpid=18968&name=Proxes%20RA-1%99&category=sport
As always, it comes back to how YOU use the car
Take care,
Ed