Cable: a rolling chair-rack.
http://www.bestfurnitureonline.com/p-84.html
Props/Costumes: wardrobe racks
http://www.hangercity.com/ducogara.html
Use large rolling file cabinets for gels and gobos, and rolling utility cabinets for tools and props. Basically, you want everything to roll. That way, with your tight space, you can put things where you need them and get them out of the way when you don't.
There are also tons of threads floating around on various storage methods. Use the search tool and you'll find some good solutions.