To protect my eye longevity, I've been buying cheap, polarized Wayfarer knockoffs from Amazon for some time now, but I'm ready to try some real sunglasses. Being an engineer, I'm more interested in performance and value than in appearance, though appearance is nice, too.

UV protection: WebMD says I want 99-100% UVA and UVB protection.
Polarization: I like polarization. It means I often have to tip them to read a phone or tablet screen, but I like polarization enough that I don't mind.
Durability: Want.
Cost: I like to maximize the performance/price ratio, so a much higher price for a small incremental increase in performance isn't so interesting. That said, much higher durability, I'll pay for.
Name brand cachet: Nice to have, but I wouldn't pay much for it. Value is more important.
My big head: I have a big melon head, so I'm guessing metal frames would be better to shape to the long distance from my face to the back of my ears, but I'm open to different opinions. Trying them on is probably not optional, so I'll need to shop at a brick and mortar store.
Am I forgetting any factors?
Anybody have any brand recommendations based on all that?
Available places to shop that I can think of: Bass Pro, Academy Sports, MC Sports, Sunglass Hut, Walgreens. I suppose if I found just the thing, I could look online for a screaming deal, but I tend to buy local when possible unless the price is stupid.