I have a Jayco fifth-wheel. I bought a set of Maxxis ST225/75R15 Load Range E tires about a year ago and now have about 9500 miles on them with no issues. I bought mine from a local, non-chain store tire dealer.
I'm not sure what load range tires came on your trailer, but going up a load range may be a good idea.
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch