I kept a fairly complete partslist with prices and part numbers of what I used.
https://docs.google.com/spreadsheets...it?usp=sharing
Mine is an 85, so there will be differences, but most of the stuff would be the same.
If you're keeping the tune/motor stock, the stock ECM is fine. You can either do your own harness (
www.lt1swap.com) or buy one. BP automotive gets a lot of good reviews, but there are others. Minimum you'll need to ECM flashed to remove the security stuff (VATS), I paid $75 to the LT1swap guy, but lots of places can do it.
If you're upgrading the motor, then the holley stuff is pretty sweet, supposedly self-tuning to a certain degree.