Yeah, they're like that at most lfs I've been too, also, at least around here. It's too bad.
I hope there will be lots of kribs in the tank to give you a basis for comparison, because it's not that easy to tell sometimes, especially if they're still juveniles. But ... look for a krib whose yellow color at the very top of the dorsal fin runs all the way to the end, and who also has a spade- or diamond-shaped tail.
Good luck!
Pat