Back when I was in the market things were a little tighter, I got most of my bits off of e-bay, and I liked the look and feel of the factory T model.
But this place does ship to Canada
http://www.hawktecharms.com/ at least the bits, not too sure on barrels.
Basically what came up on the BC barrels seemed to be a quality thing if you were luck it shot well though it seemed more often it did not.
FWIW my T model with the other bits has worked really well for me, but it is just a gopher killer, but feed it elley 10x ($20/box) and it shows.
One thing I would do different is to get a replacement sear and hammer. Dispite the typo above I just got the hammer and it is still a little creepy, the set's are supposed to reduce that significantly
Mostly it eats CC mini-mags