Hi, I am building my own house and roughing in my master shower. I want dual shower heads with an antique, industrial look with exposed copper shower plumbing (see diagram). Initially I ran 1/2" pex, but I was told I would need more volume for a dual shower, so I ran another set of 1/2" pex (it was easier than running 3/4 since I already had a 3/4"-to-1/2" manifold). So now I have two 1/2" pex hot lines and two 1/2" pex cold lines that I need to connect back together with a pressure balancing valve (per code). Would either of the ideas in the diagram work? Which is better? Is there a better idea I'm not thinking of?