Wheel sizes

[canalligators]

You're going to get a lot of arguments one way or another.  The most important factors are tire width and tire availability.  Until you get some experience behind you, I'd go with 26 because, well, many widths can be fitted to most 26" rims, and many kinds of tires are available.  And they'll certainly do the job, being the most popular touring tire.

Other factors such as wheel strength depend on a lot of variables and are secondary anyway.  And yes, you'll find people with agendas or drilling down to fine points that aren't terribly important in the grand scheme.  Not that they're wrong, but the points aren't critical.

It's kind of like chain lube.  It's almost a religious topic to some people.  All you need to remember is to keep your chain clean and lubricated, with a petroleum based oil (it resists moisture best).

[JDFlood]

On a touring bike I want a tire size that is readily available everywhere, just in case. So all my tour bikes are 700C. You can choose the number of spokes to make the wheels stronger. I use 40 front and 48 rear for my fully loaded touring bike. 36 by 40 for my credit card tour bike.