Happy for you and your new sewing space. For me if you're going to put shelves between the studs on the hallway wall, I would make the shelves far enough apart to have the wire baskets that slide onto the shelf above (these baskets can be as deep as you want or need depending on how deep your shelves are - mine hold charm packs, etc...). The other thing I would love is having some dowels that fit in between the studs (easy in, easy out), for my rolls of trips (I use on quilts and sewing of garments too). I would even see about putting in a board (a number of them), with pegs on the tops to hold my threads (again you would need different heights between to hold the different sized spools - this would also make it easy to know when you're getting low on a color of thread). Enjoy your new sewing space and all of that great light.