Best make of tire for your 29' 5th wheel trailer ?? Actually there are several very good LT tire brands for your trailer with 16" wheels and probably 5200 lb axles.
I sure wouldn't put a ST tire on a trailer that size regardless of brand.
IMO there is no best brand.
The best of the best tire type IMO for trailer use is a commercial grade all steel ply carcass such as the Bridgestone Duravis R250 or its sister tire the Duravis M895 or
the commercial grade all steel ply carcass Michelin XPS Ribs.
Other best LT tires are the Goodyear Wrangler HT or the BFG Commercial HT or the Firestone Transforce HT or the commercial rated Maxxis LT in the U-168 line. These tires are a fabric carcass/steel tread belts and are used across the trailering world including RV trailers with great success and have few if any of the ST tire type issues.