Those are super cool! Took me awhile to find some but got an Araya 7x 26'' wheelset laced to those black Shimano MX hubs with thick spokes a few years ago. You might want to try bmxmuseum buy sell. Where I got mine.
12 ga. Thicccc
The hubs and spokes came laced to really sun-faded red Araya 7x rims that were .... thrashed. This past summer I moved the hubs and spokes to new (old) 7xs that were in nicer shape. I had to drill out all the spoke holes to accept the thick nipples.