I am only a third year beek, and have been building my own frames also. My top bars are similar to yours, but I run a shallow kerf down the center of v. I find it easy to pour melted wax into the kerf, and if I want I can also wedge foundation in the kerf. I am not sure of the length of the guide, but I use 7/8" thick stock to make top bars, and use a tablesaw for all cuts. by the way I would be interested in knowing what cad program you used to draw your frame designs with.