You're honestly probably better off talking to someone like long's wheel and tire in FL or someone that could make a custom set of wheels for you. You could also go with a 22.5 or something more commercial in nature to open up more options for tire sizes.
Custom made wheels are steel and legally only rated for off road or farm use, if this matters to you. One issue with military wheels is some tire places won't touch them, again if this matters to you. A tire place that mostly does commercial will
probably touch them, something to keep in mind. If you have deep pockets you can get blank 22.5 or 24.5 aluminum wheels and have them drilled, this is a very expensive route. I do know of
a place that sells used wheels, that might work for you, shipping might be a pain, but all in all it'll be cheaper than custom made steel or aluminum wheels.
Take a look at that link and see if you can find anything that works for you.
Super single tires vary a little in size, but a common size people use with a Deuce is 395/85r20 aka: 15.5/85r20. I'm afraid I don't know if the hub on the Ford F600 is the same size as that of the Deuce, so not sure if military wheels will work for you or not.
If you do go with custom aluminum wheels I would recommend
this place, they might be able to help you with the drilling, they couldn't help me, but it can't hurt to ask.