There are many ways to do it. I have been assembling mine over time, as I have been able to find good values on equipment, and as my needs change.
I began by stalking craigslist and other classifieds until finding a good deal on a used freezer or refrigerator. I found a 14.8 cu ft Maytag chest freezer on craigslist for $75. It will fit eight kegs plus the tank.
I was also fortunate to see a post on HBT for a local brewer who was moving and selling off his 6 kegs, tank, regulator, and various fittings, including a couple of cobra taps, and bought those for a good price. The regulator has a wye on it with two gas outputs, so I have been keeping two kegs going at once with the cobra taps.
A friend gave me a ball lock and pin lock keg, tank, regulator, etc. I reconditioned the ball lock but I do not use the pin lock, even though I did get the liquid and gas disconnects with it. I have not gotten to the point where I have filled all seven ball locks, yet. If anyone within a few hours of Boston wants to trade a good condition ball lock for a good condition pin lock, let me know.
I got a Love temperature controller and wired it inside a PVC box, according to
https://www.homebrewtalk.com/f51/temperature-controller-box-portable-solution-128443/.
I am looking to be able to keep more than two kegs going, so the next project is to go from one leg of the wye to a secondary regulator and a four port manifold. This will allow me to keep four kegs at one pressure off of the manifold, and a fifth at an equal or higher pressure on the other leg of the wye. The current gas lines are 5/16, and the secondary regulator and manifold are 1/4, so I am going to figure out a way to step down to 1/4 on that leg of the wye. I believe the wye is 1/4 FPT, with 1/4 NPT x 5/16 MFL ball check valves, but I have yet to take it apart and confirm that. If I am correct, I will only need one 1/4 NPT X 1/4 barb or MFL to make it work. I will probably rig up a quick disconnect where the gas line goes into the secondary regulator.
That should hold me for a while. If I really want to be able to keep more than five kegs at once, I will probably get another secondary regulator and manifold, and put them in series. That would allow one pressure from the other leg of the wye, a second equal or lower from the other leg of the wye through the first secondary regulator, and a third equal or lower from the second secondary regulator.
The freezer is in my utility/brew room in the basement, so I am not in any hurry to move from the cobra taps to Perlicks through a collar, but I may get there at some point. Not before I get what I need to go to all-grain though.
Can you tell that I'm having fun yet? :cross: