Enthusiastic 200tdi Disco owner speaking. Mine is a G-WAC, but they are all the same really. If you find one with no sunroofs you won't have the drippage problem. As my wife says, "it's pouring down outside, but it's only drizzling in the Disco".
Chassis/body is everything with any Disco. Pre-EMS and anti-lock they are like large Meccano kits, and parts are cheap compared to any Jap models.