Their betta selection seems to be random. Males, females, tail type, fin type, etc. I was looking at a pink female (half-moon, I think) before I got Fafnir. Check in every week or so, the stock will change. You might get lucky and get one like Fafnir.
The one I frequent is the AquaWorld in Ellisville, just off the intersection of Manchester and Old State Highway. There's another AquaWorld in Gravois that's supposed to be bigger, and if the quality is the same as this one, you'll probably never shop at chain stores again.