Here is a tire that closely resembles the Goodyear Terra ag tires which came on the JBI. Looks pretty good! As with all Deestone tires, they are a bit smaller, but the pictures show it's not by too much. A pair would be right at $225 delivered. I am thinking about a pair of these for the HD-12 Diesel instead of 15" rims & tires.
Same seller also has the BKT tires, the center ones in the pic. About $245 a pair delivered. HERE
The one to the left is the tire I speak of, on ebay.