Get the Omega. I've owned many juicers, and the Omega is the best one of all, by far. It's waaaaay better than a Champion or anything else in that price range and will juice anything really well. (I mean, it does great at anything I've thrown at it : carrots, apples, greens, beets, celery, etc.)
I have the 8004 with a 15 year warranty, the best in the business. The 8003, 8004, 8005, and 8006 are all basically the same. Some are chrome, some are white. Mine has a harder auger.