I'm in the process of coverting my Z into a good (fun/capable) track car (for a few track days) but maintaining the sleeper/good for road use characteristics that I love about it.
Thus far I've polybushed the front (rear in the next week or five), coilovers, new discs (just ADL), hawk HP+ pads all round, stainless hoses, camber arms and ATE Super Racing Blue fluid. I've driven it for the first time with only the front done and the difference is night and day. I can't wait to get the rest done and get the geo setup properly
Have fun with it.
As others have said, there are better cars to start with but I like the Zed