My supplier of choice is http://www.fb-stuff.com/fb-stuff-store.html I have bought several sets and every one has been top notch. Pricing is very reasonable too. Pretty sure he will sell you just one if you only need one side.
They are a very nice white gel coat and are much stronger than the originals. I would avoid the ABS covers at all cost. Very difficult to get paint to stick the slick plastic.
I bot one set, painted up real nice. Soft and pliable. REal lifesaver over using hardened cracking old stock ones. Never heard good feedback on others, than just adequate.
