they had "appearance" packages that had the factory body kit but not the big engine or anything cool.
as far as the doors and windows i havent had to do mine, my car is kind of babied i dont get alot of the problems others have. i have done a few others though and i would say definitely fix the windows first so you dont have to fight that. mark where the hinges where on both the door and the car before you do anything. if you know anyone that works at a body shop they have door holders to do it if not your just going to have to wrestle it, i would try to get some help. balance it on a jack with a towel on it and then get the bolts in.then you have to adjust it so it closes and the window seals
1998 Bonneville SSE
2007 Monte Carlo LT-KYB, Clarion, Polk audio, Kicker
1999 Yukon SLE-KYB, Air lift, Reese dual-cam, Tekonsha
1987 Firebird-355/th400-nothing stock