Mark,

You will need as BIG of a scuba tank as you can get.

The JPX uses a lot of air during the start sequence, and since you are new to this type of turbine you will use up even more air. The size air bottle you mentioned, you'll be lucky if you can get one start from it, and that's if everything works as it should.

I used to carry (2) two 80 cubic feet scuba tanks with me.