I'm thinking that it would be best to get corners from Matthews, Avenger or American Grip and buy the tube locally. But there are lots of choices.
Should I get 1" square hardware or 1 1/4" square, or 1 1/4" round tube hardware that can be used with aluminum tubing or Speed-Rail? Does anyone know the correct alloy and gauge, especially for the square tubing? I plan to use 6' lengths with a coupler that clamps on over the outside of the tube at the joint for the 12X12, that sound okay?
I would certainly work on getting at least a pair of combos. C-stands just dont have the "ass" for a 12X12. You really need at least combos and a couple of sandbags. The square tubing should be fine for up to 12x12 i would use thick-walled aluminum then there will be no problems with rusting.
you will have a hard time clamping down the smaller heads you need lollipops. remember anytime you fly something the enemy is wind. if you are flying on c-stands or babies theere is a good chance of it getting picked up and thrown on top of somebody or a corvette or something else expensive.