Thanks Ben,
I could sort of make out that verbiage on the KDP-20 but wasn't sure about what it signified. This makes a huge difference. I agree with you. Machine #2 is worth going after, and stainless inserts can still be found for the tub door and the access panel below it. #s 1 and 4 are good second choices, if you don't mind #4's single rinse. Same goes for #4 with the stainless inserts, but not for #1. If you choose #2, take a good look underneath to check if there's been any leaking from the tub that made its way to the motor, and if so, proceed with caution.
I'll also state the obvious: condition is a huge factor. If one of these machines is in like new condition, even if it's not your first choice, it should be considered. Conversely, if any of them have been worked hard, have wobbly wash arms that don't spin smoothly, signs of rust and crust, deteriorated racks, liners, etc., they're probably being pitched for a reason (or two or three) and may require more work and parts locating than is worth your trouble or feasible.