Loonz, I went through This a couple months back. There are so many optins it's hard to pick. I would say stay with your stock size sprok n chain. Change the tooth size if you want. But then a speedo healer is needed. Or not. The new chains have a crazy high tensile strength and will last quite a while if taken care of. As far as X vs O, I went with DIDs xring VM2. Good Hunting.