I like the idea of having PSK items attached to your person, but I have never been fond of the Altoid tin type kit. They are just to small to store any real Gear. One system I have used in the past and you might consider is using a spare container for your kit. Something along the lines of a 40oz widemouth kleen canteen will hold a good bit of gear, and you can boil water in it. You can attach it to the bottom of your vest with a carabiner, and let it ride in the floor of your Kayak.
I still do this when hunting. I have one bottle with water or gatorade, and the other is stuffed with cordage, small (2nd) compass -, fire kit, fist aid, bandana, AMK heat sheet (unrapped and stuffed to keep everything from rattling), Aquamira tabs, the list goes, etc. Just thought I would share.