Maxxis ST8008 seems popular on this web although we've had 30 complaints from SDT8008 owners who had issues with them.
Maxxis ST along with the Provider ST and the new just out Carlisle HD seems to be the most popular ST tire at this time.
The Provider and Carlisle HD are the new gen ST with more of a LT design with a flatter sidewall profile and M speed rated (81 mph).
JMO but the best tire for a road trailer (40k-60k miles) won't be a ST tire.
My used 11000 lb 5th wheel trailer/5200 lb axles came with new 15" ST. I sold them on cragslist to a guy looking for a cheap tire/wheel combo for his lawn service trailer.
I bought four 16" 6 lug steel modular steel wheels and BFG Commercial LT215/85-16 E at 2680 lb capacity. The 15" spare still hanging under the trailer.
Ran the first set for 55k miles and currently right at 48k on the 2nd set. No issues of any kind.
Check around in our 5th wheel and TT forums for more input.....and lots of other rv websites for even more help with your questions.