Go to a store and try them all on, make a note of the ones you like and see if they have them on the website (whichever one you may choose). Sure it makes it take longer but you'll be more sure that things will suit that way.
since i don't wear glasses, i was blissfully unaware. i just assumed they'd cost around the same as sunglasses. i.e. 50-80 chfs for an no-name.