They're good cars but they're getting old. Finding a solid no rust car to start with is getting more challenging, an even then, it's at least 12 years old (electrical and hydraulic systems don't age gracefully). If your planning a swap, look for a '91-'94 model as the PS system is compatible with an SR20, I have a '90 and I haven't had much luck finding '91+ lines for it (at a reasonable price).

SR20's will go as fast as your wallet will allow them but the factory turbo/MAF sensor/injectors all top out around 250-275hp. There are lot of solutions out there (bolt in turbos, 300ZX MAF sensors, ROM tuned ECU's to control bigger injectors) and a little research goes a long way. The suspension aftermarket is almost as big as the Civic with every link and arm having an aftermarket adjustable solid bushing versions and springs/coilovers aplenty. Stock brakes aren't the best but there are a lot of OE and aftermarket options (the 4 piston 300zx setup being the most popular).