Howdy. I am upgrading components on my low-end hybrid. Had it about a year... frame's ok, components are garbage. Just got a dura-ace 7703 crank. I assume BB needs replaced and am planning on that. What I don't know, however, is if I need to upgrade my derailleurs to dura-ace or if say deore or ultegra will work. Also current set up is 8speed, new crank 9speed... so I just need a 9speed chain, eh? Thanks a bunch.