I just ordered the smaller front sprocket for my V4S to match the gearing from the V4R. 520 conversion with the quick change sprocket and DID 520ZVMX - GOLD chain. Sprocket Center has a great selection and prices.
I got my stuff for my 520 conversion mostly from Sprocket Centre and from some other sources as well. If you search my posts you will find pics. Not at home so do not have access to the pics on this PC. I went with a Gold chain for bling factor. You can get rid of a good deal of weight too.