Don't get it twisted now, IMO 20" isn't big enough. The Bonnie isn't my fast car, I have a LT1 if I want to go fast. I'd like to put 22s on my ride, but the 20s were $800 for 5 wheels and tires. I still plan on putting chrome on the Bonnie.
My stock L67 is quick in the GTP, but the modded LT1 owns it, and the 6 speed is fun to drive. The Bonnie is still my toy, I will not mod the Z anymore than it already is.
You only live once, so you might as well do exactly what you want :P .
BTW - My gf thought the GTP was fast, she drove the Z, and yesterday she came home with a new radar detector for me