we have a dr brand 12 hp in the atv club gets used quite a bit, never really any issues. just belts and stuff. only thing id say is if you wait for the grass to be a foot or more you have to wait for it to catch up a lot, so if you don't do it often the higher hp one would be better
If Bush Hog is still around they use to make great pull behind mowers. My old dealership was a dealer for them until they wanted us to stock their UTV.
They had a 42" and 48" cut mower with Honda engines. Also had pretty stout ZTR mowers If you could find one without the Kohler engines.