I just recently bought on Ebay a set of seven DOT 2012 8R 19.5" tires with supposedly 3,000 miles on them and one 10 bolt rim for $450.00. I was however in a quandry before I bought them as I found these.....
Rickson Wheel Manufacturing
8 hole 10 bolt 7.25 19.5x 6.75" aluminum alloy rims. These will fit a 245/70R19.5 that will give me the same diameter of the *R's but be wider and easier to buy. I have e-mailed the manufacturer to find out what the total width of the dually would be; also what the measurement would be from the back mounting surface to the back of the tire.
I will let you all know what I find out.