I just did my Red '99 GT on Wednesday/Thursday of last week. Took my time, but it took me both full days.
Here's what I did:
I did the coolant passage block (no more coolant in the wrong place again EVER), porting out of the LIM passage at the endcap, New Valve cover gaskets, NEW LIM Gaskets with metal gaskets (not faulty plastic anymore, and it came with the tube of black RTV sealant), new dorman UIM with reinforced/aluminum chimney for the Exhaust Gas Recirculation port, new PCV valve (came with the dorman UIM), new fuel injector O-Rings (6 came with the dorman UIM, and 6 came with the LIM Gaskets), new thermostat gaskets (came with the LIM Gaskets), new map sensor seal (came with the LIM Gaskets), new water pump, new heater hose fittings that connect into the LIM and block, thread sealant for all LIM bolts and water pump long bolts, and cleaning/detailing everything including all bolts (one LIM bolt was so corroded I had to buy a new one). My map sensor fell to pieces when I took it off, so I had to get a new one of those also. My coolant temp sensor also broke, but I plastic weld repaired it and is working fine.
While I was in there, I did the LIM mods outlined here:
http://www.grandprixforums.net/how-mod-lim-46931.html
The car is still hesitating, so I'm not out of the woods yet, sadly. I'm going to take another stab at it this week when I have time. I was hoping it was the map sensor, since I goop'ed it to see if it would fix, but wouldn't, so I drove to the autoparts store and bought a new one. Nope, not the map. I had also done a compression test before all the work, so I know the heads are good. I'm out of ideas right now, but we'll see.