Being cheap (about some things) I made mine from scrap pieces of fiberglass angle (like angle iron, only made from fiberglass) - I work in a plant that uses all kinds of chemicals, so they get some pretty exotic stuff, and all the "mad inventors" who work there tend to "dumpster dive" as a new project is going in - mine were made from 4" angle, it was a bitch to cut all the slots.
The closest commercially available thing I've seen to mine are these -
http://www.sweetwater.com/store/detail/CBLD/
BTW, this
Maximum cable diameter is .025"
is obviously a misprint - they mean 0.25" :=)
For headphones, you want 'em when you want 'em - again, I custom made mine (no pix, place is a disaster at this time) but one thing that would work is those single hook-type towel holders, placed wherever they will be in reach of the mix position. Don't get the glue-on type unless you have a really good clean flat surface to glue them to.
For extra headphones (visitors, talent, etc) I found some individual-sized containers made by Sterilite, called "ShowOffs" - one container, one set of phones, they stack 3-4 high without tipping, they're clear so you can see what's in them, and they keep phones from gathering dust when not in use.
http://www.sterilite.com/Category.html?Section=Storage&ProductCategory=42#
The 1892 and 1894 are the sizes I use most, 1892 for phones and 1894 for all the various accessories/pieces of a particular "goody" - example; one has all the accessories/charger, etc, for my digital camera (including the camera in a small shoulder bag) one holds my brother label maker and over a dozen label tapes, the manual/cd, the PC cable, etc - one holds my rotary laser level with targets, laser reciever, etc - for that one, I took some 2" packing foam and made cutouts so the stuff doesn't rattle around but is easily accessible.
The rest of my (organizational) life is a freakin' disaster :=((