You might want to take a look at Chacos too... they have a very contoured footbed (Z1 or Z2) with pretty high arch support (at least it seems that way to me- really subjective stuff), and it's solid rubber, not EVA, so it doesn't break down flat over time.

http://www.chacousa.com/products/performancedetails.cfm

I've got some minor complaints about them- they take some breaking in, and run a little heavy- but they work a WHOLE lot better than any other production sandals I've tried.