The On3 kit will probably fit fine, but for a show car, a kit from B&G would be a much better choice in my opinion. His kits look better, come with better components, and will definitely fit. The only catch is you'll need to wait a few months to get a kit. There are always some kits floating around on Corral from HP performance, Pony Down, B&G, Hellion, PTK...all the well-proven kits. I bought my HP kit used, but basically recreated the entire thing to make it work for my needs. You need to be careful if you have an aftermarket k-member, my HP kit did not clear my MM k-member.
If you don't mind spending the cash, I would spring for a ball-bearing turbo. It will make stupid power. A 76mm should be fine for any engine in the 331-363 range. A minimum of a .96 a/r will probably work nicely for you. There is a lot of science in sizing a turbo, but .96 a/r 76mm turbos have been proven to work very well for the stroker SBF engines. Even an 80mm will work fine, but some streetability may be sacrificed.
Do you have pictures of your progress? Start up a build thread!