Good luck buying a 79 SE four speed - I looked on & off for years before finally pulling the trigger. The search became a sickness, I had to do it when I found one.
If I were buying an 89 GTA, it'd be the 20th Anniversary Indianapolis Pace Car optioned 3.8-liter V6 Turbo. That was the Grand National motor - yes you're correct, 1555 made.