Cart upgrade advice for Music Hall 5.1

Looking to upgrade my cart in the 500.00 range, and also a compatible phono pre- amp. Any helpful advice would be greatly appreciated.
Do you know if you want MC or MM? In this price range, I would go with a good MM. Ortofon has some new ones called 2M. They range from about $100 to $700. I have a Bronze which is about $400. I am very happy with it. Sounds like a MC but not as expensive and not as senstive to vibrations-especially important in TT's without suspension. Grado has some nice cart's in your price range too.