Don't mean to hijack your thread, but I just wanted to mention...
For refilling, I've been using the same 20oz soda bottle (mountain dew, I think) for at least the last 3 years. I wasn't sure if the plastic was gas-resistant, but it most certainly is. The only part that wasn't was the seal inside the cap. I was going to glue in a piece of cork, but it wasn't necessary - cap seals fine without it.
You probably want something nicer than a pop bottle, but I thought I would mention my experience for other cheap bass-turds like me.