hi allan,

http://www.mcmaster.com great online catalog,
they got everything even the kitchen sinks !
they even have local pickup if there is one in your area
to save on the truck fees.

how about ebay, lots of tubing online,
I got some nice 6063 (higher corrosion resistance)
..5 od from a guy in california.

Problem will be the ship fees, 12' is by truck.

Got to be a local place that has it.

73 tube guy