you might check out this at discount tires http://tinyurl.com/nnfbjk7
the LT version is rated for LT265/75R16 is 3400 lbs which is awsome.
A couple of reasons we don't see this size tire used on a trailer nor a mfg option....
The 265-75 is a wide base tire with a 7.7" to 8" wide tread. With that much tread the tire will have more side scrub stress than the usual tires we use on our trailers I doubt anyone makes a zero offset trailer wheel that wide plus in many cases the tire is too wide (10"-11" section width) for the wheel well.