The secondary 4-way is what I meant to post as I may go with the beer gun in the future and want to have that as an option should I ever need it. Is that do-able or should I buy a dual regulator as a primary for beer gun purposes? I don't mind buying a primary dual regulator if I have too. Just looking to save $$ where i can.
You can do it cheaper. This is how I've built my setup, they key is 2-way manifold..
Flask outside of kegerator, meaning saving space and some hassle..
Primary regulator goes into a 2-way manifold with on/off on both outputs. One output is for burst carbing/counter pressure filling, so I don't have to deal with running gas to my counter pressure filler from inside the kegerator, it gets its gas from the outside, straight from the flask.
Second line of the 2-way manifold is run to the 4x secondaries.
You'll save the difference between a manifold and a 4th secondary regulator, even though it's not that much, but the setup is handy, to have a "high pressure" gas source on the outside of the kegerator.
On this line I've connected just a short hose, with QD. Then I have different hoses with QD's I can connect to this line. For example jjust one long hose (extender), and one short hose with a white ball-lock, and one stand alone cheapo-regulator with hose with QD in/out I use to push starsan between kegs.
So I can connect a ball lock to this line, and I can connect a regulator + ball lock to this line, and i also have QD on my gasline for my counter pressure filler and this connects to this line as well, as everhthing is with QD's. Extremely versatile, without having to go inside the kegerator to get gas.