Ladies: Know any comfy shoe websites with good return policies and wide shoe options?

I'm on the lookout for comfortable shoe options for work; I have very little arch in my foot and it causes a lot of foot pain and tense calves.

Trouble is, I have wide feet and narrow heels so it's hard to find something that fits in the foot and doesn't cause my foot to slip out. ANNOYING.

Any ideas for on-line websites with very good return policies and that have wide shoe options?

I know Zappos has some options, how is their return policy?