I am a Toyota owner also and just bought a 1996 Disco. I was also shopping FZJ80s and 96+ 4Runners. I had the exact same concerns as you re: reliability, Toyota really spoils you.
I couldn't find an 80 or 4R for anywhere near what I paid for my Disco.
Rather than writing a novel here, I will say the Discos have had issues. I prayed the previous owner resolved them and for the most that seems to be true.
They get awful gas mileage, about the same as the Cruisers. 14city/18-19highway.
I find the interior much more comfortable than the 80s I drove. Rear space is small but very tall, I find it plenty adequate for my needs (which are minimal).
These things are simple to work on - they are built off the Defender chassis which is a working truck. The "fiddly bits" can be troublesome, but the major systems are tough and easy to access. Parts prices don't seem to be any different than other makes, it all depends on where you shop.
There is one thing this truck has in abundance and that is character. You can't really be ambivalent about owning one, they will get a rise out of you one way or another. My experience has been great so far!
Things to watch for: rust on door jambs, inner door, rear door, roof esp around the alpine windows, firewall; leaking sunroofs and alpine windows; all PS boxes leak, but check to see how bad; they tend to leak from just about everywhere else but nothing too serious; exhaust manifold cracks (exhaust leaks); vehicle speed sensors ($60) seem to go bad quickly and the stepper motor (idle control) requires maintenance.
Also check
www.discoweb.org, that was an invaluable resource for me when I was shopping.
I kept my Toyota so I'd always have at least one running vehicle. <img border="0" title="" alt="[Wink]" src="images/icons/wink.gif" /> This Rover really is a blast so far!