Rick's and Northern Tool both look like decent sources. The wheels shown are mostly the common trailer alloys that are widely available, although the two chromed alloy wheels at Rick's and the 7-spoke design at Northern Tool are somewhat unusual finds. For something more closely matched to the truck wheels in appearance, I really think that rather than trailer-specific wheels, general custom wheels or truck-specific wheels are more likely.
The big centre hole needed for the protruding trailer hub is like a 4x4 truck front hub, so there's a good chance of a fit. Aftermarket wheels intended to fit many vehicles usually have big centre holes, and may be available with "centering rings" to fit them to the hub... for the trailer, you don't need the ring.
A local tire and wheel shop in Edmonton referred me to Canadian Wheel Industries
for trailer alloys (their wholesale source), but their web site has no specific information and I have not called them yet.