I have been looking in to powder coating in KW. So far, I've found
Century Powdercoating in Kitchener and
Westex Coatings in Waterloo.
Century has quite reasonable rates for bike frames listed right on their website. I've found mixed reviews online. It seems sometimes they drop the ball on customer service. I can't really tell if this is common or just a few people who are really picky.
Westex is where my favourite LBS sends frames for coating, so I suspect their work is good. However, I've been a bit disappointed by their service. I've called twice, leaving messages for the coating manager asking to get pricing info and details on what's included in terms of prep. Neither time have I received a call back.
For what it's worth, when I contacted Hugh Black of True North Cycles (they have a powder coating shop for their own frames), he suggested
VéloColour. From what I gather, that's the place to go if you want to restore a frame really well. My needs are much more utilitarian though, so it's way out of my price range. If I were trying to restore a very fancy or sentimentally important frame though, I would strongly consider that option.