Chris,
Place a wanted ad here and check your local junk yards, 6-lug 22.5's are not to hard to find used...You can probably buy 6 used wheels for the cost of 1 new. You might check school bus companys in your area as well. I got 3 NOS wheels for free from a school bus company that no longer used 6-lug wheels on any of their buses.
Make sure you get them all the same width, I think they were made in 3 different sizes (6, 6-3/4 & 7.5").
Mike B
