Some parts are still available (drivetrain, suspension, starters, alt, etc) as they are related to Jeeps. Some of the parts are not available, so sometimes you might have to supplement with jeep parts, have them rebuilt, or do your own repairs.
Some parts are not available, and you have to either scrounge them from junkyards (or find a parts car) or make other parts work, or fix them.
For example: you can't get seats, but you can get them redone (foam, coverings, etc), you Can't get a new dash, or interior plastic trim, etc. You can however, still get Carpets that fit, so that's good.
If you're handy and resourceful, have access to a big junkyard, or ask here, it would be a project.
Hopefully I haven't turned you off, cause there's a total upside: If you're really handy, can weld, and would feel comfortable rebuilding a motor, or changing over a motor, there's a stroker motor mod where if you swap the bottom end internals from the original motor (the 258 cid or a 4.2 liter) and put it in the common '90's jeep straight 6 block (a 4.0 HO engine) they will fit, and top it off with the better head from the 4.0 (hopefully FI) and make some other mods (computer, sending unit, some of the gauges, etc) you would have an eagle that could get mid to high 30's mpg, and from what I keep getting told, probably over 250 hp (I've been told around 300).
Now, that's gotta be worth the time and effort.