Go with Goodyear radials. The bias tires are much cheaper for a reason.
Radials yes for tread wear is one reason. Had a new ish set of bias plus on a trailer I bought last year and hauled to AK from the L48. Tires took a beating and no flats. Lucky maybe, but wore most of the tread off and the trailer was not overloaded.
I've had terrible luck with Goodyear Marathon radials and they are pretty universally regarded as crap. Have lost more Marathons, like 6 of them, on boat trailers than all other trailer tires combined. And they don't pop, they delaminate after getting to be a few yrs old and tear stuff up.
For radials, 14" there are only 2 D rated tires I know of. Kumho 857s like posted above. These are the best tires out there I'm convinced. I've beat the he!! Out of a couple sets for years with no flats and best treadwear out of several different brands I've had or used. They are $30-40 more than all the C rated tires cept the overpriced GY Marathons.
etrailer.com sells d Rated Kenda tires. They are cheap, $100, and better load rating than C tires but not as high as the Kumhos. Just bought 4 of them, but haven't mounted them yet so no experience. Great price for a D tire though.