Did you consider the copper nickel alloy stuff that is around now? I never used it yet. It seams a lot easier to work with.
I made up several lines over the years using a made up length from NAPA and cutting it down to size and reflaring the cut end.
I use a low end flairing tool that I picked up at a parts store. It is not perfect yet it always works. Attention to detail is very important when double flaring. Also good alingment to the terminus eliminates some potential issues.
