My .02-sounds like track times are important in your decision; I've only made 4 passes ranging from 14.15-14.5x and trapping 102-105. My 60's have been 2.4 or worse; a 2.2 would mean easy 13's. One of the GM engineers giving demos in a Stage 1 car speculated a downpipe and SLICKS would = low 13's or better. Traction mods and a fine touch go a long way apparently.
I'm at 8200 miles and haven't experienced squeaks/rattles to speak of-those may be more prevalent in colder climates. Be sure to put back money for winter tires, the factory Conti's are SUMMER only.