CJ-7 and YJ's used one style of doors, all TJ's use the same style (different interior colors if that matters to you though).
I'm not sure about JKs.
Good luck getting some cheap - they sell for insane money for what they are. I bought some wrecked ones and painted them myself - still worked out to $300-$400 by the time I finished. If I did it again, I'd buy new ones from quadratec or new unpainted ones off ebay.
thanks Terry, they are costly and somewhat hard to find, i saw some made from steel tubing on some website i might consider them. i mainly want that little bit of protection in case of an accident this summer when i pull my top off. i know they don't give much protection but a little is better than none. i have a daughter that drives my jeep some and any protection i can give her will help.
Scout out all your non-jeep junkyards, and go to the jeep specific ones as a last resort as they tend to be more educated on the prices. You are still going to pay a good amount for the hard half doors but you may find a nice deal. We found a set of Rocky Mountain Edition high back seats for cheap at a non jeep junkyard. They had just been in a wreck and had to be pulled out of the mangled TJ. The seats were just covered in dirt and had to be cleaned. Once cleaned they looked brand new. Paid a fraction of the price Jeep would have charged!
i may have gotten lucky,found a pair on craigslist for $200, says they only have a couple of dings nothing serious. gonna check them out in a couple of days, thanks for all the feedback, love jeepz!