Upfront: I just bought mine in July and have not raced it yet.
SBs seem to do better on the road courses than BBs. This is my conclusion from reviewing lap times and race results. This is also a favorite topic for people to argue about.
I'm finding that for wheel to wheel racing SCCA might require too many mods to the car for me. I was told via e-mail by an SCCA rep here in SoCal that I would run in the SP class but the car would have to meet GT-1 safety specs. I don't know about their other classes.
I am going to run in the TCRA
www.touringcarclub.com They have time trials and wheel to wheel racing. I don't know if they are in your area.
.02 advice, contact people who have raced in your area. Local assoc. do things very differently I have found. Good luck and enjoy.