Make sure that you can still get into your Land Rover with the new seats fitted - and that you can manage without the room the seats consume. I speak from experience having purchased 2 with car seats. One had Montego seats (and its engine, switchgear etc) and a number of times I hit my head on the truck cab getting into it. Even though the seats weren't particularly large I was pushed forward and needed the small steering wheel that had been fitted.
The other was a LWB - not sure what seat it was - may have been metro - again difficult to get in and generally unpleasant - came out and standard seats fitted.