Well started reading the posts but couldnt make it all the way through. But heres my 2 cents.
Ive owned/own several rovers, a 66 rhd series, 89 RRC, 92 RRC, 94 D1, a 73 series coiler, and a 00 P38 Rangie. I prefer the Range Rover Classic myself (that is based on your requirements...I love my homebuilt coiler but wouldnt want to DD it) but the 94 and 95 D1s are right up there. The 3.9 motor is a wonderful engine. Sure they were all based on the same block but the 3.9 is a true soldier and the EFI system is fairly easy to work on. The 96 and 97 4.0s had a tendency to get stuck valves due to tight tolerances so I would avoid them. Any Disco 2 or P38 is out of the picture as the electronics are too complex, in my opinion for a reliable trail rig. I wont knock the series either, great truck, incredibly simple, but not a highway cruiser.
If oil leaks bother you and you dont want to ruin your driveway, stop now. If you arent mechanical, stop now. These trucks like the wrench if you wheel them, but what truck doesnt? The weakest link is the drivetrain...toothpick axles and weak cross shafts in the diffs. Second weakest is the electronic windows, seats, etc. Third is the Fuel Injection but more because it's tricky to figure out sometimes. On the other hand, the drivetrain (minus axles) is tough. My 89 has over 300k on it. The trans was replaced at one point but the original engine still runs strong. Just DONT overheat them... They are also overbuilt with very sturdy frames and good suspension articulation.
Ive never owned a Yota but I would pencil them as overall more reliable. The axles are stronger too and they come with locking diffs. Hard to compare that to the Disco or the RRC. The LC with diff lock is extremely capable. A locked/axled D1/RRC is also extremely capable, but is it any better. I cant say it is. Just drive a few of each and get the one that suits you best.
Would I drive a Toy, oh hell yeah, but I had to have that damn 66 series RHD 12 yrs ago and since then logic was tossed out the window! Cheers Gordo