Help me select a cartridge. I have an SL 1210mk2 with an AT 120E cartridge that I bought new in 2009. Still has the original needle and no new needles are to be found. So its time for a new cartridge. I've looked at the Grados. Starting with the Grado black, green or blue. What's the difference? Ortofon red, I see it can come mounted on an Ortofon headshell. I know little about the latest line form Audio Technica. Their VM series now. Whats their equivalent to the 120E? Shure M97 Maybe. What's the best fit? I have a Yamaha A-S501 with Polk Monitor 10s. The Yamaha was just bought and is in transit at the moment. I been leaning toward a Grado. Green possibly. Also what's a good headshell for it?