Contact Radney Foster's merch person and ask if they sell it? I can't find it either, but he has it on his official YouTube channel.
His regular version is good. I'll probably buy that one. But once you hear the tower mix, well..
I checked it out.
Since I couldn't find the origin of the Radio Tower version either, and noticed he had it posted to his official YouTube as well, I thought maybe they would have a mechanism for you to buy that version. If not, perhaps they would give you the blessing to raise the Jolly Roger on it if it's fan art that isn't commercially available.
Or, I could buy the original version.
Then capture the remix.
Then the singer get's his $$$