Polarizing filters for camcorders.

I use my Panasonic HDC-SD20 for filming river wildlife footage etc. but would like to get better shots into the water for salmon & seatrout spawning.Currently I use my oversized polaroids and white balance once that's in place. It works, but it ties up two hands and makes for awkward shots. Does anyone have any pointers or recommendations as to the best place or brands to chase for polarizing filters? I'm also interested in adding a good manual zoom lens to the front end for tripod work, does such a thing exist for these wee cameras. I don't want to have to use the work cameras like the AJ-HDX400 etc as they're too vulnerable/ big & bulky for the 'combat' environment and carrying extra cards & batteries is a faff.