Eliminators and XLS and Laredo are the top trims and the most rare. Pioneer, X and Chief are middle. SporTruck and Custom are base models. Not all these trim levels existed in every year.
but you could order just about anything onto a lower trim. I had a base 86 with AC, the bigger engine, 4wd, and the metric ton package.
the majority of all Pioneers were 2wd. Eliminators were all 2wd until (I think) '89 when they could then be had in 2 or 4wd.