shopping for libertine footwear essentials

Recently I began shopping for the Elusive Black Slingback. The reason I say "elusive" is that:

1. I have long skinny feet, and few stores carry narrow fittings.
2. It's sandal season, but I would rather have a closed-toe shoe so I can wear hosiery; also, toenail polish is not allowed in shaolin class.

I did some reconnoissance on the Web and came up with this shortlist:

I'm leaning towards the third one down (or third one up - same difference). Although it could be argued that it's not technically a slingback, I liked the detail. But one cannot go wrong with Manolo Blahniks (fourth one down) as long as you don't mind being poor. Any opinions?