Hi Rick - Another thing you might consider is what I did, which is to buy the Zeagle Razor combo reg/valve but install it on a standard pony bottle of your choice (I used a 19cf Luxfer). The Zeagle bottles are good quality, but they only offer a small 6cf and a rather squat 20cf bottle. The 19cf Luxfer (or Catalina) plus the Razor makes for a very streamlined pony system.
And you may not really need the separate fill adaptor - you'll find that the native fill port on the Razor is actually a very standard paintball port, and many dive shops have a dedicated paintball whip already handy for their compressors, no adaptor necessary.
Obviously, check with your dive shop first, and keep the yoke fill adaptor in your bag just in case. Better yet, spring for Zeagle's transfill adaptor for the Razor and don't even worry about shop fills - just fill it from your own tank.
I got my Razor reg from ScubaToys online, but any Zeagle dealer should be able to get you a good price on one. It may be a little more expensive than a separate valve & reg, but it's a LOT more streamlined!
Good luck,
>*< Fritz