Go for a Mitsubishi Shogun 2.8 turbo diesel.
Go for on that's age ranges from an R reg (98) to a V (99/00)
They can be had for as little as 1500 pounds but the best thing would be to aim for one that's done about 75000 miles, full service history (or as near full) and is immaculate inside and out.
I believe you'll be looking at a maximum price of about 3500 pounds or less.
They're solid work horses and have a reliability record bar none.

