it's obvious the OP wants lighter wheels than he has. so....

kinlin xr270 rims (20h front, 24h rear), sapim race spokes, alloy nipples, novatech hubs.

the V profile of the rims will compensate, IMO, for the lesser spoke count.

anyway, it's not as if parts aren't readily available while touring. i recently had to catch a ride due to the fact i exhausted my supply of extra tubes. it wasn't the end of the world. it didn't stop the tour. in fact, i enjoyed the challenge and probably made the tour more memorable.

on another tour, i discarded my original set of 650c wheels (built by a pro), after about 2000 miles, and built myself of a set of MTB wheels (which fortunately fit) when passing through Gainsville Fl. another memorable experience.