If you really want durability go with a Kris Holm unicycle rim, they come in black 36 hole, but are rim brake capable. Though at 38mm wide I do believe they are wider than your tires which might pose a problem. Ok enough with the jokes.

Velocity VXC should in theory be available 36H in black. Halo Freedom are probably too heavy/wide for your use. Velocity Blunt is also too wide I would think. Stan's ZTR Flow is another available in 36H but probably too wide. Sorry I think all my mountain bike rim knowledge is generally useless for you.

Another idea is the DT Swiss TK 7.1, but I'm not sure if all the disc only and 36H can be combined in one version.

Good luck in your search.