Something like this :
View attachment 160923
Also how much psi should I use?
There's many factors here. Your country, the size of your tank, the gas you're going to use, etc.
Regulator: The regulator needs to have a fitting that works with the standard in your country for gas tanks. That regulator uses a CGA580 fitting which is the US standard. If you're in a different country then you'll need to find a regulator with the fitting you need or find an adapter. Along with fitting size that regulator is using CFH instead of LPM so you'll need to convert to LPM.
Flow: The flow you need is dependent on the gas you're using and the flow meter you have. Nitrogen through a nitrogen meter flows different than Nitrogen through an Argon meter. I'm assuming you're using Nitrogen because it's easy to obtain. If you are using an Argon flow meter you will want a flow rate of 13 LPM (27.5 CFH). I've attached a chart with the conversion factors. You need at least 15 LPM of Nitrogen flow for CTB. You can see that an Argon meter with Nitrogen will flow a factor of 1.19 more than it's reading (13 x 1.19 = 15.47), or if you reverse it that a Nitrogen meter with Argon will actually be flowing .84 (15 x .84 = 12.6 round to 13) of its reading. If you have too much flow with too little of a tank you will run out early. If you have too little flow you will not reach the correct gas concentration. Either way results in brain injury and failure to CTB.
Tank size: The absolute minimum tank size you should be using for CTB is a 40 Cubic foot tank. You need 45 minutes of exposure at the correct concentration to CTB and 40 CUFT is the only tank big enough to do that. The math: 40 CUFT to liters = 1132.67 Liters | 1132.67 Liters / 15 LPM = 75.51 Minutes of flow. If you have a tank that is larger than 40 CUFT then it is okay, probably recommended, to increase the flow (I've seen talk of people doing ~20 LPM but I never followed up on that), but make sure you have enough flow for 45 minutes.
I would recommend you take a look at the Inert Gas Megathread as well! There's tons of stuff I didn't cover here I'm sure.