Be forewarned
Your experience flying CRJ and BE-1900 should explain why your being interviewd to fly a B747 that fly's everywhere in the world. The more experienced people would not touch Kallita if it was the last employer in aviation. And with limited knowledge flying widebody jets that are broken, to international destinations you haven't been too, is setting you up for either an accident or incident that will ultimately result in the loss of your hard earned FAA certificate(s). Which at that point will end your chances of working for a real airline.