16/20 spoke wheels is too trendy light, you should sell them before they break.
A) a hub, compatible with the rest of the drive train, . you don't say what that is..
B) a high quality rim, say, a Mavic Open sport, there are dozens
and have a good wheel builder put them together.
(apparently the services locally are weak on that)
[14 gage straight spokes are fine, DT/Sapim/Wheelsmith, a good brand  of spoke]
sport touring there should be a 32 spoke front and a 36 spoke rear,
or 2 36 spoke wheels.
I built a 40/48 spoke wheelset for loaded international touring.
but I expect the bike is wrong for that , given the stock wheels are for narrow tires.
There are hundreds of people who build wheels by hand, for a business.
a professional wheel builder set to ship, anywhere, when finished is Peter J White, in N H.
I rode this last year and doing it again this. Some of the roads were pretty crappy as you are going through farm land. There were a wide range of bikes and all seemed to get through the route OK. Getting new wheels would probably be depending on the type of riding you currently do. As for spokes, oder online if you LBS doesn't carry.
The mechanic they had last year was great and worked long into the night to get people going again.
If you see me I'll have the Diamondback with the yellow fenders