here you go Jon, this is Thorn bicycles brochure for a 26" Sherpa touring bike with recommended tires. Small tires for light loads and smooth roads, fat tires for heavy loads and rough roads. Between $10 and $70 there's a tire to fit your needs. Pick one for each wheel.
http://www.sjscycles.com/thornpdf/Th...paBroHiRes.pdf