Hi,
Just to add to what the others have said (thanks Chris for the plug).
Your standard 80 can do what you want in standard form without any effort so the most important thing is to make sure it is well serviced. You need to budget about £500-600 in parts for getting the axles stripped and fit new wheel bearings, CVs (if required), seals, check the diffs and diff locks, check the brake callipers, fit new pads, etc. Some of the bits can be bought cheaply from Milner Offroad, but you need to pick and choose a bit, reverting back to genuine parts for things like the inner axle seals, inner hub seals, wheel bearings, etc.
If the brake disks are close to needing to be replaced, consider upgrading them - you will be grateful once you start going up and over the Atlas mountains a few times fully loaded.
If you get an automatic - again it makes life easier on the mountain roads, makke sure you fit an extra oil cooler for the Auto box - Kenlowe do a kit for about £124.
Once you have sorted the running gear consider a suspension upgrade - Old Man Emu springs and shocks, a steering damper and then caster correction kit - you can get soome guide prices from the
http://www.tbruk.com website.
Like Chris, I would question the need for a winch and winchbar - when I was there last year I didn't see any local tour vehicles with these fitted. Having said that if you feel that you need them, again look at the TBR website for prices - I use them as a main supplier and they are pretty competitive - if you are going for an electric winch, you should also consider upgrading your batteries and possibly even adding a 3rd and a split charge system if also running things like a fridge.
If you can get a roofrack at the price that Becky quotes, jump at it. Normally you can get something like an African Outback one for around £550 and the lower level and then prices go up from them.
Have you thought about what year 80 to get? Or anything else about the car?