Sorry I have not responded in a while. Couple long days at work. I appreciate all the responses about the temperature of my boiler temperature going down so much when the house circulator kicks on, and I may plumb in a tempering line between the supply and return (not sure what size I need and if I need the valve).
But on another note, I feel I have veered too far from my original question. I know some people have responded to my original post with various answers, but I just need to know if my drawing of how to plumb the new zone will work.
I have included a updated drawing with the types of radiators and the sizes and I have labeled them S, M, & L for easier viewing with their sizes next to them and I have listed them as the Cast Iron and the 2 Copper Fin tube Baseboards. I have included a picture of the Cast iron type of radiators that I have for reference.