Lets not get off track here. This OP trailer came OEM with LT235/85R16 on 6K axles. Some one would have to be living under a rock for the last 15 years to want to go from more reliable LT tires to ST tires on a trailer that had OEM LT tires. Some people posting here need to go back and read the OPs info on the trailer. This is a 32.5 HH II LS triple slide with a GVWR around 14K.
FE can not even make the case for such a change. His pile of rules and rigs has no chapter that he could use to try to force such a switch.
OP has stated that she is tired of tire failures and that " I travel alone, and feel that I need the best tire I can afford to put on the rig."
So if she can only afford a poly carcass LT like the trailer had OEM then the Firestone Transforce HT is a good choice. If she truly wants to put tire problems behind her, then the Bridgestone Duravis R250 steel ply carcass is an excellent choice. If cost is not a big issue then the Michelin XPS RIB is the way to go.
ST tires do not belong in this thread, other than someone was not smart enough to avoid them before she bought the trailer.
I really need to replace the 12+ year old spare on my truck and the 8 year old spare on my trailer and think that I will get the Firestone Transforce HT for those two applications.
Here is a nice list of some available choices and pricing comparisons.
http://www.tirerack.com/tires/TireSearchResults.jsp?customSizeSearch=&width=235%2F&ratio=85&diameter=16The R250 still gets my vote as a bullet proof offering for her.
Chris