Hi Marc, welcome. You can tell from my 'name' where I'm from!
If you are interested in a mouthpiece I'd suggest you go the the GR site
http://www.grmouthpieces.com/ fill out their questionnaire and send it to Brian Scriver, he is the GR Marketing guy and lives just North of Toronto. He can help you!
Look for an Olds trumpet, like a Recording, Mendex or Super. Great horns for, normally, and excellent price!