Gunfighter, I've got to agree that your bench is the best design. Our club had just flat benches with no restraints. However a cord looped around one of the boards and then over the tail works well. One other thing I like about our benches is that there is a 1" board on the top on both edges. Kind of a curb to keep you from slipping a wheel off one side. A couple of us were talking last fall trying to figure how we could modify our benches for the stakes like yours. Our benches is 1x4 planks on 2x and4x frame, so just drilling the top wouldn't be to good. However a couple 2x's under the bench would provide a good support for them. What it the spacing on your holes?

Don