Mike Barry (of Mariposa) said as an advice to up & coming frame builders that "there is no money in it". It's a tough business, and it's even harder in a high cost-of-living city like Toronto. That might explain why there aren't any builders. Biseagal is the closest thing to a custom builder but he also runs a shop and the output is low, as far as I know.

Try to do some math. An experienced builder can build say 100-150 frames a year? There is at least $350 of materials and basic powdercoat in a frame, rent is expensive (unless you work at home), tooling up an efficient shop can easily add up to 20k, plus comsumables, insurance, etc. And since your are starting from scratch you need education and/or practice time...

PS. check this thread