Cassette HG 51, which chain? I need to replace my cassette (Shimano HG30 8speed 11-32) and chain (KMC Z7) that is currently on my bike (pinnacle Aura), however these parts are now discontiuned and I need to find the replacments. I have been recommended the HG51 cassette but don't know which chain to get.  Can anyone help?
Any 8-speed chain should work. If you want to be absolutely sure, get one made by the same company that made the cassette. I believe Shimano still makes several 8-speed chains.