[shoesense]

Given that your trip is in the southwest, warm season, I think you should consider sandals. There are great comfy options out there--Naot, Birkenstock (I know, I know), Chacos, Thierry Rabotin. The thing is, what suits your budget, style, and needs? I personally would go with a Cole Haan G-series sandal; their molded insole gives me plenty of support, they're comfy, and they're quite attractive.