You shouldn't have any problems. They may validate your UK license. I went up this past summer with a FAA Comm/Inst. Helo. Had to do a full commercial checkride + 100 question written exam. The main thing here is to find a prospective employer. They have to put in a request with immigration after proving to the satisfaction of the bureaucrat that no suitable Canadian is available. It's off season now, so that may be a bit hard. You could go for landed immigrant status, then look around. Some bigger operators are Canadian Helicopter, Helijets, and others. Try this site
www.avcanada.com or
www.avcanada.ca (can't remember exactly). If you want temporary, contract, like I did, wait until Jan or Feb and start applying for the fire positions.