Is the mag mount available separately at stores?

I've been trying to find a way to mount a waterproof, digital point and shoot camera on my sit-on-top kayak while fishing the rivers and inshore ocean areas. I came across your products at Pro Photo Supply in NW Portland. They were unsure if the mag mount was available separately. I'll need to fabricate a post to mount it to the kayak but the pan and tilt feature will be very helpful as I intend to adjust the camera angle throughout my trips. I'll be using a Panasonic TS1 so the light force magnets and a locking collar should be plenty.

Is this something I can purchase separately or do I need to buy the tripod with it? Also, after trips on the ocean, would a fresh water bath be sufficient to prevent corrosion?

Thanks,
Jay