I'll second the birkenstocks - no doubt the most comfortable
shoes/sandals I've ever tried (once they're broken in). They do make
shoes also, including hiking boots and safety shoes with steel toes -
they cost a lot, but worth it in my opinion, and you might find a deal
on ebay.
I haven't tried the anti-fatigue mat yet, but now that they're on sale
at Rockler, I'm going to very soon.
Andy