According to one of your earlier threads, you've had the original ST's for six years. Since they've lasted that long trouble free despite exceeding their speed limit, one would think you'd be satisfied with their performance-?
That aside:
I'm betting that your trailer has 13 or 14 inch tires. Nobody makes an LT that fits rims that size. Kumho makes a 14" trailer tire that is also sold in Europe (but not in North America) for vans. It doesn't say "ST" on it. It might fit the rims if they're 14", though I believe it's a little taller/wider than typical OEM ST's. Fit in the wheel well may be problematic.
Best advice: buy good quality ST's and slow down.