This is what I have.
http://simpletire.com/catalog?select=1&brand=83&content=42138&meta=14&loadindex=129
They also offer a military discount. Any tire shop can install and balance them.
Use the steel valve stems because of the pressure. I ordered mine Mon after 5 and they arrived Wed morn. They give shipping quotes. I saw a listing the other day for a 80 width which was exactly the same diameter as the Towmax/Marathons.
Some have asked about the load rating, mine are marked as LT tires and are rated 3750 lbs @ 110PSI. Since they are on a 7k axle I have plenty of spare room. The new ones are marked ST and have a higher rating????
I looked around and found a few dealers that carried them but the price was way higher. You can arrange with a dealer to install them and have them shipped to the dealer...
Have fun. I'm enjoying mine.