+1 to Merb and Eros.com has a section for Montreal, also P411 .... need to dig in my 'Canada' advertising bookmarks for more.
Okay more for Canada esp Montreal .... lyla.com (
https://www.lyla.com/vbulletin/forumdisplay.php?f=70), sweetmontral.ca is supposed to be another good Montreal agency, girl-directory has listings under Montreal, merc.ca (more of a review board).