As far as the pannier vs. trailer thing goes, I'd say the choice depends largely on
the sort of touring one has in mind. Panniers are great for road touring; placed fore
and aft, they make a stable load with a bit of a weight advantage over a trailer.
However, on wilderness trails I prefer a single wheel trailer. mine is homemade, but
looks essentially like the 'BOB' trailers except that I have added a thin sheet metal
brush guard to the curved forward section. As my main cargo container is a clear
reinforced plastic tub, it' easy to locate things and keep them dry. I don't worry
about snags or heel strikes from a shifting load; the durn thing even floats if the
stream crossing's deep enough, ( not a good thing in a strong current ). For my
purposes a trailer is simply more convenient.