do what i did, let the cables run where they need to run and make sure you have enough slack round the back
then fix them to where they need to go and simply cover the exposed wires with some plywood over some battons and paint, paper over the top

i you screw them into place you can also have the added effects of wood paneling in the room

i fucked up a bit though as i did everything and then the wire for the amp got pulled out by junior so everything had to come back out again