We have an absoulute maximum budget of £4000 but we would like to spend less.[/quote]
Don't know what standard of Toyota you'll get for that budget. Without wanting to kick the old hornet's nest again over "the best car for overlanding"... oh what the hell,
1 Short trip/one off
2 The budget is fairly rigid
3 You're UK based
a 300tdi Land Rover Discovery is a lot of car for your money.
1 Comfortable and roomy, even at motorway speeds
2 Air con if you want (but more expensive)
3 Cheap (P reg with MOT can be had for £1000 which leaves cash for mechanical prep (more later)
4 Reliable once you've covered the usual failures (see 3)
MAKE SURE YOU:
1 Get the timing belt changed AND the P shaped gasket behind the water pump done (this is one of the main causes of water loss/overheating/head gasket failures and can be quite sudden)
2 Have a close look at the radiator header tank for splits and change it if there's any doubt in it's integrity (this is the other main reason for sudden water loss/overheating/head gasket failure - they don't just "go", contrary to popular opinion!)
3 Change all oils/fluids and if g/box oil is burnt or unduly metallic, change the box, and the clutch while you're at it
4 If any of the door locks are "lazy", change them. Otherwise they just wind you up!
5 Welding should not be an issue if the MOT is legit
6 Check suspension - springs, shocks and bushes. Renewing the lot will not break the bank using standard parts, even genuine LR parts, and as it's not a RTW trip, you don't need gas shocks, polybushes, lift kits etc, and there's no need to overload with fuel, water roof tents/racks. Keep it simples! After all, the rest of you will be on bikes - think how much kit you would carry normally.
Of course, there are decent Mitsubishis in this price range, but the ability to detect their faults at the high mileages involved is the preserve of much fewer people than the Land Rover fraternity.
Other than that, for that money, DON'T be tempted by a TD5 LR product. It WILL let you down.
Suzuki Vitara not a bad prospect (SJ/Rhino would just be miserable for the long mileages, likewise a Niva unless your partner is a masochist)), Isuzu Trooper if you can find a good 2.8 or 3.1.
From the left field, have you considered a quad
Right, let's see what they make of that!