Cathy, looking again at the third and fourth pictures on this page, why couldn't you make a U with the walls of the room for the machines you will use the most, and that is your sewing area? Just line the machines up along the wall, either parallel to it or perpendicular, and have a chair with wheels for the inside of the U. You might have enough room to make two skinny U shapes. That would mean making a column of machines down the middle of one big U in order to divide it, and that arrangement would give you a lot of bang for your buck. It would be especially good if you had enough room to have machines back to back down the middle of the U (I guess it would be an E shape at that point.) Am I being clear enough? (I just love designing sewing rooms.)
Cricket