When you see a fish species you like, I suggest you run the species past us. Store people are generally very unreliable, and if you end up getting something that will tear into the cories...not good.
I have had some interesting experiences asking store staff about fish I saw and did not know anything about. Once it was a tank of small loaches, can't remember what they were, but I knew nothing about them beyond the obvious (need a group, soft water). I asked the lady and she said they remain very small and are peaceful. I managed to get the scientific name from their invoice, and went home to research. Turns out they are anything but peaceful, and got close to 5 or 6 inches. They stayed in the store. If I had put those in any of my room of tanks, it would have been disastrous.
On another occasion, same store actually (and one of the better here, independent), I spotted four what looked like a pencilfish in a tank of wild caught rummynose tetras. I asked about them, and the person told me they looked like siamese algae eaters. I didn't bother to point out that a by-catch with wild-caught rummynose tetras from SA was unlikely to be an Asian cyprinid. Anyway, I did buy these because I was fairly sure what they were, and she gave them to me for the same price as the rumys since she didn't know what else to call them. They were Nannostomus digramus, one of the rarer pencilfish. I have kept 9 or more species of pencilfish so no surprises, but it shows how little some of these people know. Always research before purchasing.