I've got all the blades from Crescent Knife Works in Vancouver. The roughing J-blade cuts as well as the finer ones.
Cariboo Blades in the BC interior. Kestrel Tool and North Bay Forge south of us in Washington State.
That's about it. Several on the East coast, one admitting that they copy Kestrel designs.
Making Haida style handles , long ones, is pleasant work. Far better leverage for carving.
Size. Hold the handle in a fist grip, palm up.
The tips of your second and third fingers should just touch the fat ball part of your thumb.
For me, that's a blank of 7/8" square.