I totally recommend a high tech walking sandal. I have a pair of men's rockport walking sandals, but there are many to choose from. Hot sweaty feet are the worst in my opinion, and having to wear socks with tennis shooes just adds to the heat and friction.
I am eyeing a pair of running sandals that are available now and I believe they are made by Ecco.(Yes, made for long distance running)
If sore feet will ruin you trip, than an investment in a super comfortable pair of shoes will be worth it (although the running sandals that I have had my eye on are around $100)
On our last 12 day trip, I was the only one without blisters the whole trip. The rest of my family refused to go to the sporting goods store to try on sandals. They will before the next trip!
With sandals, no wet squishy shoes!!!!!