Gen 2 turbo hardtops are damn near impossible to find. Next is the sunroof and t-tops are most common.
I have ttops, and I race my car at autocross regularly. I don't find the ttops to hold me back much. The car is very competitive, and I think you'll find others will tell you the same.
Good condition turbo's are hard enough to find these days. I wouldn't let the roof type determine whether you purchase one or not. If you find one in good shape for a decent price, go for it.
Good luck
Frank
P.S. I love having t-tops. The performance I lose from having them is well worth the fun and enjoyment I get out of having them on a sunny, summer day!