In my opinion, limiting the number of evolutionary items available was one of the more annoying aspects of the Pokemon games. Want a Kingdra? Ok, enjoy only having the chance to get one of them. I don't know how game-breaking it would be to offer the items at the Celedon Department Store considering the evolutionary stones are available for sale, and if we can get Jolteon, Arcanine, Vaporeon, Ninetales, and Victreebel by this point, the other evolutions shouldn't make too big of a difference. Having the items in the Elite 4 store wouldn't be too horrible, though, as my main desire is simply to have them for sale somewhere.