As for the CO2 bottle: Idealy you will have the bottle positioned vertically. If you do need to lay the bottle at a low angle or horizontally you will draw liquid CO2 from the bottle. For those that play paintball the solution to this is to use an expansion tank. Basically this is a small, vertically mounted chamber that allows the liquid CO2 to turn to gas before entering the rest of the system's plumbing. A google search of expansion chambers will show you what the paintball guys use. With a little ingenuity you could eith plumb one into your system or build your own. Good luck with your build. It already looks like a winner!