I agree with Rustomatic. Streetability is so subjective. I used to drive an 11 second street/strip Nova with a nasty solid cammed small block, 4500 stall and 4.56 gears and drag race shocks and springs every day. It loaded up idling occasionally in summer, didn't have a heater for winter (in south Florida), was so loud a radio was useless and cruising on the freeway at 60 was at 3500 rpms. On a good day it got 6 mpg, but I still drove it every day. That was in the early 90's. Then I got married, started a family, and that all stopped real quick. One of the coolest things about a Pro Touring car and modern technology is that you can have an engine with 100 hp more than my Nova had, get 20 mpg, and idle with the a/c on all day long.
As far as suspension goes, again modern technology says you can have your cake and eat it too. From Speedtech's point of view, little things like rotating updated front suspension engineering and geometry, "Articulink" arms and torque arm suspensions help give amazing response but a smooth, stable and comfortable ride. Decent coilovers can have heavier spring rates and aggressive track valving but when you dial down the valving you can ride home from the track like it's a Caddy.
Until I tore it apart for upgrades I drove my Pro Touring G body Cutlass daily and autocrossed it whenever I could. Even used it to tow my Nova from Georgia to Utah, covering 2500 miles in 3 days. Ran comfortable and I didn't feel beat up and sore when I got home. I say if you build it and don't drive it, you couldda saved $50,000 - $150,000 and put a poster of someone else's car in the garage instead.