Well since I got a shout here, ill give some advice. <3 Hater.......
Its a whore, and one slow car. If your looking for speed the z31 is gonna be kinda hard to get to impressive levels. Especially since your getting the n/a. How much do you have to spend? If your only looking to spend 1k, get ready to spend some more on maintanence, as its probably not in too great of shape.
The turbos dont have THAT great of an aftermarket either. Well, compared to the Z32 and Z33 I mean. Check
www.amzperformace.com , they have a pretty good Z31 area. And I know the owner personally (Hes my sponsor, well, if I decide to actually mod my Z that is)
And Z docs and Z fever are horrible. Try going to Delegance. Those guys are amazing Z specialists, and won't fuck you over like Z Docs or Z Fever will... Z Fever told me that it was going to take 2.5 hours to do my shift bushings and shifter plate, because they had to use a lift and it was going to cost around 200 in labor. I ended up doing it myself in 30 minutes at my house, and didn't even need to jack it up. They are assholes.
And yes, I do know alot about Z's. Bitch.