Now hold on a second guys. It sounds to me like the OP's light isn't worn and crapped up, but more like it's cracked, and full of water moisture that is fogging it, in which case the only real fix is to replace the lens.
I'm not sure about that second place, but the first link is an Amazon.com store. That means they are probably pretty reliable, and if you have any issues with them you have recourse through Amazon. Also, Amazon switched to a different billing system recently where your seller doesn't get any money until the they provides shipping confirmation with a tracking number, so you have a much easier time getting your money back if you don't get what you ordered.