Crossing the border sucks so I'd avoid anyone from the US BUT your dollar will go further there so you might want to do the math and see what shipping and customs will run.
I always have to give BJ props cause his customer service is 2nd to none. He was working on an 880 so you might want to give him a call.
As far as CAN motors you have SledShed, Split Second and Terra Alps to choose from, there's probably more but those are the ones you mainly here about.
I know there's a guy running an 885 from Split Second I believe and he seems to love it, haven't heard a lot about the other 2 but I know SledShed's 800HO BB (860) is a strong runner.
JAWS is supposed to have a set of pipes for the xp so if you don't want to fork out $1800+ you might want to look into the pipes. Has anyone heard anything on the pipes yet???
If you don't do a BB I would suggest an RKT head at least.