Wheel durability is more about the skill of the builder and less about the exact component selection... If you want good wheels, you need to find a good wheelsmith... or learn to build your own wheels.

That said your best bet, if you're not concerned about weight, it a deep cross-section rim (think: Velocity Deep V, Kinlin XR-300, etc), double-butted spokes (DT Swiss Competition or DT Swiss Alpine 3 if you're paranoid), and brass nipples. I'd go with 32 spokes in front and 36 in the back, laced 3-cross. I'm not sure if any of the online builders are trustworthy. I bought my last wheelset from BF member psimet2001 and they've been terrific, but he's a one-man shop (at leas when I ordered) so it can take quite a while to get anything (even an email) from him.

After buying the psimet wheels I learned to build my own, which isn't as difficult as it might seem. Wheels are not a maintenance-free item, especially for a Clydesdale, so having the skills (and tools) necessary to maintain or build them isn't a bad thing...