Another vote for upgrading to 15" if you can.
Your still not going to find an American made ST tire, but you have many more options available.
Take a look at Gladiator QR 25 TS, I had to replace my tires on our cross country trip last year, the tire shop had one tire that was a direct replacement and the Gladiators. Both are made in China, but the Gladiator was one aspect ratio and two load ranges higher than the direct replacement. The Gladiators have a much stiffer sidewall and a deeper tread than any other ST tire I have looked at. There are a lot of commercial and delivery guys using the Gladiator truck tire in my area and all that I have talk to are happy with them.
I wore the Towmax tires out in less than 3000 miles, the Gladiators now have over10k and look like they will do that and more again.
I know all the LT tire folks are going to be jumping all over me, but so be it. When I need to replace my tires again, I'll be going with the Gladiators.