Okay, lets see if we can't get your questions answered.
1. Like I said in my previous post, I have two gauges so I know how much pressure is left in my tank. With the built-in gauge on an SCBA tank, you don't need the extra gauge.
2. You don't need the needle valve because the SCBA valves can be "throttled" just fine.
3. Some rifles come with a fill adapter, some don't, ask before you buy. None that I know of come with the Foster adapter, more in just a minute.
4. No, the Air Force rifles do not have gauges on them. With a single gauge system, the gauge shows pressure ONLY when the gun/gun tank is connected and the filling tank valve is opened. When you crack the filler tank valve open, the gauge needle will rise quickly to the remaining pressure left in your gun, then continue rising slowly. In the case of the AF rifles, max fill pressure is 3000 psi, but most do better at a lower fill pressure. It's up to you to monitor the fill rate and level and to close the valve when you reach your selected fill pressure level. Then you open the bleeder valve to dump residual pressure left in the hose or whatever.
Go back to Joe's web site and look around, then give him a call. Tell him what you're getting, he'll get you set up with something like this:
http://www.hamcontact.com/airgun/HoseAssembly/hoseassembly.jpgThis is all stainless, include the hand tight SCBA fitting, bleeder, gauge, micro-bore hose, and female Foster quick connect on the end. Two more pieces, the brass adapter for the Air Force fill adapter (also from Joe), and the Air Force fill adapter (order it with your rifle), and you'll be set.
Two more quick items. If you really feel like you have to have a regulator, Joe can set you up there, too. Talk to him, like I said, he's a good guy, and will make sure you're set up the way you want and need. Second, if you're going to own an Air Force rifle, I strongly advise you to get a chronograph if you don't own one already. Yes, you can shoot one "out of the box", but for optimum performance, you need to make adjustments, and to do that effectively, you need a chronograph.
Finally, if you haven't found it yet, here's the link to the Talon/Condor forum:
http://talonairgun.com/forum/ Tons of info on the Air Force rifles, and some pretty good people to help answer questions. You might want to start by reading through the Quick Reference section, it'll probably answer a bunch of questions you don't even know you have :-). Later.
Dave