IanOn: There are any number of sources. Your choice will depend on how much you're willing to spend. If you're just looking for a holster to wear on the range for plinking, you should be able to find one for $100...maybe even cheaper. A good quality, long lasting holster won't be cheap, though. So be prepared for sticker shock.
Simply Rugged, has already been mentioned. Very traditionally styled holsters, if that is your preference. Then there's Marstar . Several reasonably priced offerings listed. If you're looking for a Canadian-based custom leather maker, there's: Working Cowboy Leather (Chatham, ON). Another: Leather Works Canada. You might even be able to find something suitable, in Cabelas.
Most of the top leather makers though, are in the States. Mernickle has already been mentioned. Excellent quality. Then, there's El Paso Saddlery. Doc Noper. Kirkpatrick Leather. Tombstone Leather. Plus many others.
If making your own appeals, there are any number of tutorials on you tube, showing the process.
Just a short list, but enough to get you started.
Al