Tires are priority #1, especially if you're going to be adding more power. Stock suspension w/ good tires will easily blow away upgraded suspension w/ RE92's or cheap tires.
You might want to check out whiteline's Anti-Lift Kit, it reduces understeer caused by powering out of corners.
If you want to get rid of body roll, swaybars are an easy way to do that without sacrificing much ride comfort or ground clearance.
After that, drive around and see what you wish your car did better. If you want more power, wait for the turbo, because other mods aren't going to make much difference compared to that. For something that would help a lot down the road, check out phenolic spacers. They help keep the intake manifold cool (cold air = more power), which will be even more necessary when you add turbo.
Don't go buying a super-strong racing clutch; it's better to have a slipping clutch than a broken transmission.
Might be nice to have seats or at least a harness. It's amazing how much easier it is to drive when you're not clinging to the steering wheel for dear life.
And brakes are important too. At the very least, upgrade your fluid and pads when it's time to change them. Then get some stainless steel braided lines, then consider getting into the big-dollar brake systems.
-scott-