Call Shine Racing Services at 508-660-7974 or www.shineracing.com. They are just about the best, they have been building winning VWs in IT, Prod, and probably a whole bunch of stuff that I don't know about.
They will have your answers on everything....from tires to sunroof removal.
I have no vested interest in SRS, but they have always been more than helpful to me.
BSI Racing all the way, bolt it all on (buy the entire kit) use Stu's settings and win races. One big reason also to use Stu and BSI is the support after the sale. He will keep you up front with the latest valving and adjustments. No one better for the A2.