I too am upgrading the tires on our Greywolf 26BH since the factory Trail Express tires on our 2012 are starting to weather check already. I stayed with 14" but went up to 215/75/14s (load rating of 1870lbs vs 1760 for stock 205), and went with Hercules tires as I was able to get them locally and they are atleast a brand name that I have heard of before. I am thinking about upgrading the rims to aluminums, purely for looks.
Good luck, happy camping!!
TT-2013 Passport 3220BH
TV-2004 F150 FX4, not exactly stock...
with 2001 Kodiak K215: 2010-10, 2011-12
with 2012 Grey Wolf 26BH: 2012-19, 2013-24, 2014-11, 2015-6
with 2013 Passport: 2015-13, 2016-15 booked