I am currently getting set up to do the same thing. I plan to use the same dual pressure regulator and a manifold, though. One port will go to a 4way manifold. The other port will just have length of gas line and quick disconnect to force carbonate a keg. It may cost a bit less to just split the one port 4 ways with tees, but it will be a lot neater using a manifold. And a you can get a 4 way manifold for around $40 which is not bad considering the cost of the regulator, faucets, shanks, etc etc.