There are tons of options. I offer a few simple options, but to really get into it where talking lots of $$$, bigger displacement and so forth. There is already a V6 turbo in europe only.
18" wheels have been done. Most go 17" to be on the safe side and for comfort of ride. 18 is no problem with a 10mm spacer on the rear but a 235 is about max.
Chip, headers and exhaust can boost the car nicely without sacrificing too much as far as reliability/longevity if that concerns you?
Larger valves, port and polish and possible some C&B cams may be another step, then there is moving up to a 3.2 or even 3.5. Anything is possible.
Welcome to the BB!!
Jason