I had 15" wheels and ST tires on my 09 Wildxat 27RL.
I upgraded to 16" wheels and put LT tires on my Wildcat.
I ended up getting Nexen Roadian CT8 HL 225/75R16E tires. They were priced great and have held up great to over 7,000 miles of towing this past summer. I tow at 70 to 75mph (tires are rated for 115 mph) and I camp in the back country which means I often tow (slowly) over roads that require a 4x4 to get to the good boondock sites.
The Nexen tires are made in Korea and believe it or not, I'll probably switch to this tire when my tow vehicle's tires wear out. I like their impressive 15/32" of thread and wear since new is very good.
LT tires do not have the same capacity as ST tires of the same size. Make sure your replacement LT tires have equal or greater capacity than what is currently on them. This often requries going up one size in diameter.