I've seen a good amount of that particular type mixed in with normal kuhlis. Next time you see normal kuhlis in a tank tank a good look to see if they are all the same species.
You may just have to tell the fish store employee to let you net the loaches so you grab the right ones. I found some at VIPets if you have one in your area. Also look into special ordering from a more local pet store. Talk to the person in charge of ordering fish and see if you can work something out.