Whichever kit you can find that you can afford.
The big three are:
1. ATS, these were the factory kits on 93 and 94.
2. Banks, this is what I have on my truck.
3. Hypermax, I have no experience with these, but lots of folks run them.
Unmodified, they will all give you about 10 psi of boost. They all work well in making these trucks do hat they were meant to do.
Buy what you can afford. Research it, and make sure you get the WHOLE kit. Nuts and bolts can be hard to find.