Just bought a great trailer that has the original tires (10 years old).  They are Goodyear Marathon ST 225/75 R15 Load Range D.  The trailer is a 2003 Exiss Event XT200 - 2 horse slant gn. 

I contacted the tire dealer where I got my Firestone Transforce LT tires on my LQ trailer.  They are suggesting STC Hi-Run ST tires and say they do not have a LT tire in that size. 

Can anyone suggest a good brand for me to look for?

Go back with the Marathon radials like came on it. If they havn't blown out in over ten years, they can't be too bad of a ST tire.... Those Hi-Runs will probably last about 2 to 4 years at best. They'll rot, crack, break belts and blow out before you ever wear them out.

Got a set of 16" High Runs I would give you off an Exiss if you come get them. Funnest wear I have ever seen. At the correct air pressure as stamped on the tire, they are baby butt smooth in the middle of the tread, but still have 3/4" or more of tread on interior and exterior sides----looks like they are greatly overinflated, but they are not!!

Waiting for them to blow, take a fender off, start on fire and ruin a rim or two before I replace as I tell the SO. Why not have some excitment????