May I hazard to recommend Palladium boots, and their inspiration, the French (AFAIK, also often listed as Israeli) (now surplus) desert army boots.
I don't have experience with the originals but I have a Quechua version that continue to serve well as my hot weather boot. Unlined cotton so breaths very well, the rubber toe box is enough protection for your bottom digits, they're light, and because they're boots no troublesome stones to magic into your shoe.
As for 5fingers and suchlike, I think a correctly chosen shoe that allows space to naturally splay your toes is going to be as good for your feet and also afford you the flexibility of wearing socks and using it in colder weather. You can get 'toe socks' (I own a pair I bought in Japan as tourist tat) but they're a pain in themselves (too many stitching lines on mine).