I like the Blue Sea System Cable Clams.
You can see it as the one round thing on my deck. You punch anything from a 1/2 inch to a 1.25 inch hole on your kayak depending on the clam size and the connectors you use. Mount the cable clam (in your chosen location) and run your cable thru. They are serviceable, adapts lightly curved surfaces, you can change FF cables easily, and I have taken out the cable entirely and capped the cable clam with a thin round cut out rubber and it looks very clean.
/bing