Originally Posted by PeterM1
The LSD is a very good starting point, it'll save you from a lot of near-future aggravation.
Both the StarSpecs and the RS3s will be more than fine for your track events. Now is a good time to decide sizes, as both the tires you listed as $250+ in 18s are available for less than $200 in 17s. Tires and brakes will be somewhere on your list of top track expenses, and trust me these add up very quickly.
+1...especially tires AND brakes.