If it doesn't have to look like a "sgian dubh" you've got a whole world of options. I am quite sure back then, when everyone carried blades all over Scotland, there was a huge variety of sgian dubhs. They didn't all look more or less the same, like they do today.
With that in mind, I decided to shy away from the traditional look a little bit when I'm sporting a kilt. I currently use a Benchmade 180 Outbounder. Sometimes a Kabar ESKABAR, which will soon have some custom wood scales to make it look the part a little better, instead of the black cord wrap. I've also dropped my TOPS Blue Otter into my sock. I've also got a Koyote Sgian Dubh, and I like it, but it ended up a little bigger than I want. I can't complain about Christof, though. His work was fine. My specs were bad for what I actually wanted to use it for. LOL.