I haven't looked at the 305Z exhaust, but the chances of it fiting over the rear suspenson, around the gas tank, and having it match up with the cats is very, VERY slim. Just go to a good muffler shop with a mandrel bender, and have them fab one up for you. It will be about $300 (guessing), but will be alot less hassle.
EDIT: and welcome to the TCCA man!!!!