Have you tried to just clip it to your belt without a holster? It's what I sometimes do. The whole point of such a small light with a clip is to not need a holster. Or is there some specific reason you cannot just clip it to your pocket or belt? Just preference?
I would recommend clipping it to your belt if you haven't tried it yet. It's much more accessible and convenient in my opinion. If you liked the holster that came with the light fine, then there are lots of generic holsters just like it which are sold on eBay and amazon under all kinds of names. I cant really recommend a specific brand since I tend to prefer a different style and the holsters I use are all are for lights much bigger.