I bought my first cab several years back from a place in Burnaby called Canadian Coin Machine. They have quite a huge warehouse stuffed with hundreds of cab in various states of repair. Their website seem to be down, so I couldn't say whether they're still in business, but if they are they're probably your best bet. If you do go with them, do a little research and be very savvy, as they will try and charge you as much as possible for an empty cab. I definitely overpaid when I bought mine due to inexperience and lack of knowledge.
Canadian Coin Machine Distributors
Address: 108-3680 Bonneville Place Burnaby, BC V3N4T5 - Canada
Local: 604-420-4008
Toll Free: 1-877-236-2646
A quick search also turns up another company in Burnaby, Canadian Amusement Game Supplies. Don't know anything about them, but their website seems to indicate they have a lot of stock in the arcade business.
http://cagsonline.com/cags.html