I’d only use DID, EK, RK personally
Best price 145 shipped from super bike supply.
http://www.superbikesupply.com/mm5/merchant.mvc?Screen=PROD&Store_Code=SBS&Product_Code=drive-systems-520-yamaha&Category_Code=520-conversion-yamaha
Motomummy
https://www.motomummy.com/store/home.php?cat=601
Riders Discount is were I buy 90% of my stuff they have pretty sweet set up for sale cost a bit more then the other links.