I would wait until the autumn/winter period, when the plant is dormant before moving it - say mid October onwards. I agree that 12 ft between plants is good, but you'll get away with 8 ft. The stems that have fruited this year can be cut down to the ground, the stems that have grown fresh this year are the ones that will fruit next year. You could select the plant/s you want to move, and cut the old growth now so there's less top growth when you do come to move it. You could also at this time, take a sharp spade and cut into the soil to at least a spit's depth all the way around the plant, at a diameter of around 2 ft. This will sever some roots and encourage fibrous fine root growth before you move it. keep it well watered until you move it. Before you move it, erect some sort of sturdy framework - posts and wire are good, this will give you something to which you can tie in the new stems. If you have room, tie them in on one side of the frame, then next year when new stems start to grow, you can train them to the other side, thus keeping old and new stems apart and making it easy to prune down old stems at the end of next year. Good luck.
