I went that route. With a big concentrator, and tanks. What a PITA. I now have a InogenOne G2.
I ordered mine from this site. http://www.inogenone.com/medical_oxygen/#.T1ACzfVOb3A
I used my credit card. And it's mine. No oxygen script required. I got the traveler's pkg. And I now have oxygen, anytime, anyplace, or anywhere.
I take it walking, hiking, shopping and off roading. Can go on any airline, and it good up to 10,000 feet. And weights about 10#'s with battery, and carrying case.
No more tanks rolling around in the storage bay, leaking oxygen.