Good tire selection. I had the Kumho 857's installed in the spring and they have performed great all summer. They barely get hot even towing at higher speeds. They are speed rated to 99 MPH.
I don't recommed towing that fast BTW.
I paid extra $$ for them because I wanted the 8 ply 14" tire since the 6 ply were overloaded with my setup. My old tires would get pretty hot with normal towing speeds. Now I have peace of mind while towing without the expense of moving up to a 15" setup.