Originally posted by Tom S. Have you considered a Coken filter system? I'm pretty sure they make one that large in the "P" series. The glass isn't as optically clean as a Hoya (besides, it's not glass, it's plastic), but if the only reason you want it is for protection, you can slide it in and out for use. Additionally, they make a bunch of other filters to fit the holder, which if you were buy in 82mm would bankrupt you.
The Cokin CPL is utter crap. It is even worse, than the even cheaper Kood CPL (which fits the P-Holder). Any good quality old linear polarizer, which you may find cheaply in the junk box of a photo shop, will provide better colour rendition, than a Cokin filter.
Ben