Not sure what part of the Metromess you're located in, but Kinney's Muffler on Pipeline in Hurst does pretty good custom exhaust work.
You're just looking for any old set of springs to slap on the Konis? :shudder: There is a lot more to coherent suspension tuning that just slapping on a set of springs and letting her rip. Before I'd offer you any advice, I'd want to know what your intentions for the car are (daily driver, weekend cruiser, autocross car, track car, a little bit of all three, etc.), and how many miles you typically drive it in a year. You may think that brain rattling springs won't bother you, but if this car is your daily commuter you'd be suprised (spoken by a man who has commuted in his track cars for the better part of the last five years) just how quickly that gets really, really old.
More importantly, unless those Konis have been revalved, they're going to be pretty worthless at damping really track-ready spring rates, even if they're brand new.
As for wheels, it appears that Tire Rack still offers the Kosei K1 in a white finish. The 15"x7" model is $129 each. These wheels may not be the lightest or highest tech wheels out there, but they're a good, solid, near-bulletproof wheel that will stand up to almost any punishment you can dish out at them. Good looking too (imho), in a classic sort of way. I owned a set, and I'd buy 'em again.