I actually purchased a kit from NoSleep Studio to put a plasma system together but got distracted by moving house
I purchased the PBC linear rails from Motion Industries Canada (Motion Industries - Keeping Industry in Motion) and they were helpful with quotes and I was able to pick up from their warehouse. I don't have the prices handy, but you should be able to get a quote from them.
The V bearings I purchased from Ball Bearings:Miniature bearings:Ceramic Bearings:Bearing since they ship to Canada.
Like you, I have found it hard to locate suppliers in Canada and have switched to using a cross border warehouse for a US address and just picking the stuff up from there. This depends on how close you are to the US border