In my opinion, its not the lines, its the fill station. Fill station o-rings are a regular pain, because they get damaged, blown out, etc. Just keep a bunch of them on hand and get good at putting them back in.
As far as the coupling, I am a big fan of the Bauer and Compressed Air Specialties QD's. They are both safety quick disconnects, and will not blow the o-ring out, and the line wont whip if there is not a tank on it. They are pricey but well worth it for the safety and convenience factor.
The o-ring that goes inside the QD is a #10 o-ring. I ordered a bunch of them from oringmonkey.com
Central Alabama Paintball Park and Tournament Complex
Minor League Paintball (MiLP)