I don't have a recommendation for a sandal, but I will agree with the recommendation to shop online. You'll find a wide range of styles and sizes.
Zappos.com
Shoes.com
Shoebuy.com
These are all reputable online retailers. The great thing is that they offer Free Shipping and Free Return Shipping. That allows you to purchase several pairs of shoes without intending to keep all of them. Sometimes I will order a variety of styles and keep what I like best. Sometimes I will order a certain style in a couple of sizes and keep what fits best.
Whenever you know what you want to return, you simply go to your account on the website, identify the item(s) that you want to return, and print the shipping label on your home computer. It's very easy and convenient. You'll get the refund on your credit card when they receive the returned package.
I do find it helpful, also, to read the customer reviews on these websites.