How wonderful to spend 25 days in that area. My one suggestion would
be to plan to spend at least long enough in Zermatt to take the train
up to Gornergrat. The trip is nice, but at the top the views of the
Matterhorn and the glaciers are just magnificent. Zermatt is one of
my favorite places ever, and no matter how often I go I have to take
the train to the top.
Have a great trip, take a warm jacket and shoes with traction. There has always been snow and ice up there when I've been at any time of year. Sure sounds good to me.
Lou Matthews (sweltering in this Texas heat)