Yup, what BigJon said. I uses to think I was the man, having outsmarted everyone by only spending $3. Then I tried the FZ1 mirrors and was forced to recant. There is nothing that can be done to an OEM FJR mirror to make it work as well as a FZ1 variant. Sorry.
As far as where to buy them, I would suggest boats.net. Someone else may have a better suggestion. Check eBay, but DO NOT buy the cheap knockoffs. Buy 1st Gen mirrors. 2005 and older, just like the FJR.