Sticky at the top of this section called LEVEL 5 IRS is a good read. Search Full Tilt Boogie Racing on Google if the SVTP search isn't up. Search IRS Tech Article on Google or SVTP. Really though, I've only been doing serious research on this car since I got it in January - it doesn't take long to really know what you have...the best platform ever.
Depending on how baller you want to go the Agent47 SLA is a good buy for the front end, double A-Arm front suspension, comes with Penske Coilovers, CC plates, all the goodies. I'm considering picking one up myself as I plan to build mine for the road course.