I'm not sure of what finished size room you need but suggest you start with the longarm. Research the one you are interested in and get the measurements. You will want at least 30" on each side and the same on at least one end. I had my longarm against one wall on the end which worked. After I moved I didn't have to do that and it is nice. I got plenty of exercise going around the whole thing all the time. My longarm is on wheels so I could put it against a wall and move to the other side when I wanted to change from front to back or the reverse. I never had to do that and would avoid it as it is just more work to deal with. Once you know how much room you'll need for a longarm you can add to the space to create your full sewing room.