I grew a Dixie and a Triumph decades ago on a 10x12 arbor, each planted on opposite corners. Each season they grew together so thickly I could get up there and walk across them. Tons of fruit. I wouldn't recommend braiding them and I would give them a little more space than one foot as well. After a few years the "trunks" get pretty thick and gnarled. I would use #9 galvanized wire and a couple of 8' 4x4 posts buried 2 feet deep. Those vines can really stress whatever they're growing on. Good luck!