Custom racking out of some plywood - that way you can make it to suit your gear, as well as the shape of your van. If you don't have the time/skills then search eBay for "*VAN MODEL* plywood racking" - you'll find premade racking for most popular vans at a not too bad price.
As for cable, I've got a couple of cargo nets stretched over my lower two shelves - keeps all the cable where it should be.
A forum sponsor supplies racking and bin solutions if that was of interest ? Don't know if they do member discounts though. Van Storage ? Filplastic UK Ltd
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc