-- Last Updated: Jul-17-12 10:06 PM EST --
Sorry no pics. As long as you have some weight in the bow you won't need any counter weight. You will need weight up front. It may tend to lean if you get out.
I have a commercial model made for a Grumman. I got rid of the clamps and bolted it through the gunwales once I found a position I liked.
Old Town Canoe or LL Bean sell a pretty good one.
Some guys use a 2x6 or 2X8 and leave the transome end full width and cut the part that goes across the canoe(gunnels) to 2.5 to 4". Then bolt or clamp to the rails.