This is the model that is probley the closest fit.
ALUMINUM RADIATOR GM CHEVY 16" x 28" LOW PROFILE - KMJ Performance

However if you would like one that is designed for the Disco then take a look at this one.
Allisport Discovery V8 Direct Replacement Alloy Radiator with Two Oil Coolers | eBay

 

So many things needing work on this 03 D2, I was running out of funds in a hurry, so, thinking a new radiator without the usual leak at the upper mounting screw, was a good investment. Looked more or less identical to the unit that came out of it,....and so far, so good. No leaks, other than that pesky upper radiator bleed screw, and and temps right in the middle of the gauge on 100 degree days.

 

The temps will be right in the middle - because the gauge is made to show that spot for about 130 -240F. Please check with an OBDII connected scanner to be sure, look for coolant temp.

 

Thanks for the heads-up on that Buzz. My Scanner shows 197-199 while driving and 201-203 while idling with a stock thermostat.

I Looked at 180 Degree Thermos,....seems to me they were $65 and I decided to pass, since the truck wasn't overheating when I replaced the radiator (it was leaking from the upper mounting point where the screw goes into the tank,..my last Disco did the same thing)

Brian