Tradewind (single axle, leaf springs, 5200# Hadco 4" axle) came with 15 inch wheels and the original specs say 700 x 15 8 ply truck tires. I had problems finding 15 inch truck tires with enough load rating that would fit the wheel well. Same problem, too wide.
Last fall I replaced the original wheels with 16 inch from Low Cost Trailer Supply
(WH166-60E, 16" x 6, rated for 2780 lb, 0 offset, 6 on 5 1/2 bold pattern) and went with BF Goodrich Commerical T/A radials
(LT215/85R16/E). It is my understanding they discontinued the load range D tires, but I've had no problems with the LR E ~ 2500+ miles on them to date, they fit, ride smooth, and everything in the coach stays put when traveling.