Basically, if it is not a Landrover badged vehicle, do not even consider it. If you've lots of people and things to move around go for the 110, if not; the 90-either in whichever derivative and year your bank balance can survive the blow. However, the newer the plate the less chance you have of successfully maintaining it if that is within your capability. TD5's are all very nice but watch out, its a plug-in for service- watch those £££'s rack up! Forget the moans about this or that isn't up to scratch-its meant to be like that-that is why it is the best off-roader bar none; which is what you have asked for. The best buys in 90's are the last of the 300tdi engine versions of which there are a few to research re. trim levels etc. The engine is as damn near unbreakable as an anvil with a hammer. Every LR has parts which wear out and need replacing-just depends on how you use it as to how long they last but, at least you can buy them and either fit or have fitted without breaking the bank. If you are going to use it in any way seriously off road and want to go more than in a straight line then it has to be a 90 as the bigger jobbies including range rover and disco tend to fall over sideways a lot. I see you are in Yorks. and there are plenty of off-road businesses there who will help you if you contact them. If you think I could give you more help let me know. I drove Landrovers for over 10 years in competitive off road events all over the UK(I also drove some lesser cars which regularly let me down in many ways) and was never seriously let down by one. Put simply, they are the very best of the very best.
Tom.