I use a Renthal sprocket on the front only because it was cheap and a Sunstar sprocket on the rear. I have a DID X-Ring gold chain that runs on that. AFAIK Sunstar are the people that make the OEM sprockets for most of the Japanese manufacturers, I've never had issues with them and the prices are good. If I can't get Sunstar sprockets I try to get JT Sprockets or Renthal ones (not aluminium ones.) The gold plating on the DID chain does make a difference, the normal ones tend to corrode quickly. The corrosion isn't an issue it just looks crap, the gold one stays neater. Wouldn't buy a gold one again unless I find one cheap again. As long as the sprockets are carbon steel they should be fine. DID chains are probably the best value for money. Avoid Renthal chains, I've read and heard many bad things about them. Their sprockets are good though, but consider that there is no need for getting hard anodised aluminium sprockets on a Strom. I'd say anything between £80-100 is probably a far price for a decent set of sprockets and a good chain. Shop around, I usually get them for in the £80 somethings.