I've been to Kitchener Starter and Alternator they do good work. If you bring the alternator to them turn around time could be same day if they aren't too busy.
However I Honestly recommend buying a High Output Alt from the states.
I bought mine from
Excessive Amperage - High output alternators by C.S.A.
180.00 Amp Output. Been good for last 3 years of abuse. Also It was just under 300CDN shipped. It came via USPS to avoid duty charges.
Good Luck.