Just a thought: why not simply redesign the system? Salvage the parts that you like and buy the rest from someone like Spirit or RPM, CCR, whoever. It looks like the existing system wasn’t right, never seen anyone tee the reservoirs together. Plus, having hard to find or mystery parts that may or may not be up to the task... not good, in my book. I have built fast cars in the past with sub standard brakes and they are not fun, they are cumbersome to drive and dangerous. Build a solid, safe ride. No offense intended, just my point of view.