Full disclosure, this will be my first GM truck and first GM vehicle since I've started to really learn to be a mechanic. I have no experience with their names, trims, or ease of repair and maintenance. So, I've had it with my Ford F150 and I'm tired of trying to guess what'* wrong with it or being told I'll have to pay $200 to have some numb nuts take it for a week and tell me what'* wrong only to then spend an arm and a leg to buy parts to do it myself. So, I am switching things up. How are the generations of GM trucks arranged and how is part availability and interchangeability? I heard a term "GMT800" being used but I'm not sure what it'* supposed to be. According to Deboss Garage, the parts change out pretty easy and computer software is cheap and easy to get a hold of. What years could I get for a few grand that should still last? I know previous ownership plays a huge role in reliability but what about failures associated with time and poor design? Don't spare me details. I'm not a dumb mechanic and I'm no expert either. I'm ignorant of how GM designed and built these trucks. My expertise has been in Ford and Blue Bird, and my shop wont touch anything except coach side of the vehicle on Ford chassis'. My shop will work on A/C, warning lights, emergency exits, and body power on Ford. Feel free to send links to sites or videos that already have this kind of info on it.

I infer you are interested in the newer ones like 2000+ so here'* a couple of good places to start:

https://en.wikipedia.org/wiki/Chevrolet_Silverado

https://en.wikipedia.org/wiki/GM_GMT_platform#GMT_800