It is best to have a vaccum hose coming of each runner tube, and have them all go to a canister of some sort. This canister then becomes balanced common vaccum, and can be used for brake vaccum and everything else. The factory 20v has this setup if you look closely, but you wouldn't know it unless you look because it is cast into the manifolds and plenium bits which you probably don't have on the 16v.
If you run the fuel regulator off one line, it may pulse. Balanced vaccum would be best.