Nice room.
I'd suggest a folding cutting table.
http://www.joann.com/joann/catalog/p...DID=xprd830869 JoAnn's sells them, as do other sewing/quilting supply sites. I love mine. They can be folded down & take up little room. It has wheels, so it's easily to move. Mine sits up all the time tho. I got the big cutting mat to go with mine. I used to crawl around on the floor too, but no more. They aren't big enough to lay a full size quilt on, but it's much easier on the knees & back & great for cutting.
My sewing room is in a small bedroom, with a tiny closet. My huz says it's dangerous in my sewing room, LOL. I have a big old metal desk with one machine sitting on it, a 2nd machine in a sewing cabinet. My serger sits on the end of the cabinet leaf. My coverstich machine is sitting on a file cabinet & I have to move/set it up where the serger is when I want to use it. I have a folding cutting table, 2 sections of stackable shelving. There's a path from the door to my machines. Small TV up on the wall. I purchased heavy duty plastic shelving at Lowes & a rolling cart (got that at Wal-Mart) with 5 drawers. I also use the very large totes that I can stack on the floor. On one of the shelves I have smaller stackable totes for other items. I tend to buy everything in bulk, so I have separate totes for marking pencils, elastic, thread, buttons/snaps/etc. I quilt & do garment sewing as well, so I have tons of sewing items. I'd love a bigger room, but that's not possible. My industrial sewing machine is in a 2nd bedroom, that we also use for exercise equipment & it also has a full size bed & file cabinet. I have to move the one exercise machine to use the sewing machine. We're crammed in.
What you choose all depends on what it is you need to store. One idea may be to have some sort of movable shelving built for your storage closets. Sort of like kitchen pantries, where you can pull them out & shove them back in. You might be able to buy pre-made shelving & add wheels to it. I'd go look at the options at Lowes or Home Depot & see what you can come up with. They have plastic & metal shelving. I think you can also get wire bins, which could be mounted to shelving. These sites might give you some ideas on what's available(look thru all the catagories):
http://www.containerstore.com/welcom...FYs65QodFjrKCw
http://www.organizeworld.com/
A design wall (I don't have one)...maybe you could have someone make you a fold down wall on wheels.