Looks great, but it's going to beat you to death off-road with a rigid fork and 20" wheels.
If getting there is more important than getting somewhere fast, looks like you've got it made.
I had a pair of Alex 48 hole 20" wheels, that had press-fit bearings, flatted axles, and rims that were aluminum alloy and about 1" deep, double wall. They were noticeably much heavier than standard wheels, but were very strong, and so tight you could ring them like a bell.
Something like this Primo BMX 3/8" 48 Spoke Front Wheel Hoffman S&M Standard Profile Federal GT DK | eBay