For £3,000-£4,500 you could get a very nice DSE. As with any car over 10 years old you should be prepared to do some maintenance and will need to be reasonable with a spanner. It is also a good to befriend someone with a good diagnostic machine.
If you are not short on money a 4.6 HSE is a brilliant car. I got one in pristine condition last year for half your budget. I had to sell it though as 10-11 MPG is not nice and my first name is not sheik
I have 2.5 DT at the moment and it has had issues (immobiliser problem) but what with the snow falling here, I would not swap it.
Near you on Gumtree:
http://www.gumtree.com/p/cars-vans-motorbikes/2000-w-reg-land-rover-range-rover-dse-76000-miles/1008771751