Well, the key stuff to learn about the 80's -
1. They ride better than 60's
2. They are cheaper to lift than 60's (3" for under a grand to a grand vs. $1300+)
3. They have slightly more room - but the back seat is actually less roomy cause of the third row seats.
4. FZJ ('93-97) may have head gasket issues
5. FJ80's have same engine as FJ62's.
6. '93-'97 have factory axle lockers available, which make them stock more capable than pretty much any other vehicle
7. The Lexus LX450 (like mine) is pretty much identical, sans some body cladding and options.
8. Plan on building sliders yourself unless you have a spare grand sitting around, plus a couple hundred for shipping.
9. '93-97 have rear brake calipers that won't allow use of 15" rims.
I bought my 80 a year and a half ago for 11K with 163K miles on it. Within six months the bottom kinda dropped out of the 80 market, and they've come down considerably. FJ80's, other than being dogs and not having factory lockers are pretty nice, and dirt cheap. I think you'd have a hard time finding one over 5K asking price. The FJ's are certainly dogs, but they'll still climb a tree, they just take longer to get to the tree. I'm a little biased, my bro. had a FJ80, and moved up to a FZJ80, both of which he bought from my dad who is now driving a LX450 (kept trading down miles). And of course, I have my LX. With the lockers I think my LX was probably equal to my 40 off-road, back when I had street tires on the 80.
My brother had a really nice 60 series before his FJ80. Spring over OME suspension, HF55 tranny, with an underdrive gear splitter, a fuel injected 350, and 35" tires. I really didn't like the way it handled. It always felt tippy to me. Boy, when you stepped on that 350 though, it certainly moved. He had twice the money into that as his current 80, and his current 80 is twice the vehicle. The 60 is still a good solid vehicle. My dad had an oportunity to pick one up for around 1500 in good shape, and I wish he had. There is something about the way the 4 spds on those click into gear. The 80 is just real easy to get to the level of 35" tires and high capability for a vehicle this size. My brothers 60 on the OME suspension before the spring over rode pretty nice, almost as good as a stock 80. But it's still a leaf spring suspension, and there are limitations. On the 80 the limitation is the radius arm front suspension. If you're going big, like 38's or 40's in tire size, I don't know as though it maters which you start with, cause you're going to be custom doing alot.
Anyway.... I'm long winded while waiting for meetings to start.... If you ever want to check out my LX, give me a hollar, I'd even let you take it for a spin.