I have purchased trailer tires several times over the past 4 or 5 years for my two trailers. Each time I did some research. As to the Greenballs, I believe they are now made in China. Some folks seem to have great results with them, others complain about them. But that seems to be the rule for most trailer tires, even Goodyears. So, like the rest of us, I guess you will have to "spin the wheel" and hope for the best that you get a good set.
That said, what I have purchased and drug down the highway at 65- 70 mph, over a few curbs in tight spots (oops) etc. have been
Maxxis M8008 ST tires. I purchased mine from
Discount Tire Direct . Right now, other than running a Michelin LT (truck type) tire, they are the tire I tend to recommend based on my experience and research. I believe that they are a Taiwanese company. Some folks have problems with them too, but most seem to be like me, very happy with them.
I know you want to keep the money local and I respect that, however, I would do some research and make sure you are happy with what you are buying (and maybe that will be the Greenballs).
On topics like this I always suggest checking out RV.NET (same as Trailerlife Open Roads Forums, Woodalls Open Roads Forums and I think Good Sam forums that share the same forum under different names). Airforums is super, but
RV.NET, has many more folks posting as it is a general RV / SOB site and is great for stuff like tires. Of course as always you need to sort the wheat from the chaff.
Good luck and safe travels no matter what you decide to do.