2002-2005 Range Rovers with the BMW Navigation system (not Jaguar touch screen) can use BMW's Hybrid Digital TV tuner found in many E39 (5 series), E46 (3 series) and E53 (X5) models. Just search eBay and you will find them! It's a straight swap plug and play and a very easy swap!
I've had mine for 3 years and when it works its great but here in the South the digital signal has yet to be "cranked up!" so I guess the jury is still out but a couple of things in its favour are 1/ It still has a built in analogue tuner so you are no worse off and 2/ you can cover a chunk of the cost by selling your old analogue tuner!
Hope this helps,