I bought this little kit:
Off of E-bay the other week for 80USD (140 msrp but we all know that's a general rip-off price). It came with 10ft of silicone hose, a plastic bubble counter and the paintball regulator, ready to be fitted onto a standard US paintball tank.
I bought this set up for my 5g fluval spec in my dorm room.
Very solid construction, smooth paintjob. Easy set up as well. You twist the regulator on and plug it in to a timer and you're ready. My particular reg came pre packed with 50psi working pressure. So that means it should work fine with atomic co2 products.
The needle valve: It's a full stainless steel body needle valve. I inspected the internals with a flashlight and it's brass on the inside meaning if you were to tighten it too much it'll break and be no good. So far adjustments have been pretty easy. Opening the valve is a little tough at times and you might end up opening it too much but I haven't had trouble getting it dialed in. The needlevalve is a standard compression fitting but I installed my own 1/4" steel checkvalve onto it so yes, you can use that JBJ style bubble counter with it.
The freebies: standard silicone tube (this stuff leaks co2 but it's trivial unless you have like 50 feet of it running across a room). Plastic bubble counter; trash with really spaced out threads that leaks gas. Get something better (or just not use a bubble counter since those are pretty useless unless you have an RG style reactor).
It's being used with a fluval ceramic diffuser since I hate glass diffusers (break all the time, can't stand wear and tear, obtrusively large)
Below: JBJ style bubble counter base w/ check valve installed. I don't use a BC because they always leak and when you can just see the fizz coming out of your diffuser there's no point. The "X Soap" thing is from me tripping soap water all over the junctions to test for leaks btw.
Preliminary feelings: It looks solid, feels solid and isn't really ugly and obtrusive. For small spaces like kitchen counters it's probably a good bet and a half way decent deal. It's still cheaper in the short run AND long run to use a pb adapter and a normal regulator but if you don't have this space it's not bad. I've used other regs (azoo, milwaukee) in the past and they've all more or less felt the same. I've only set up for a day so I'll update with how well it holds up bubble counter over time.