No mater what you do with the wiring your still going to have hoses all over the place. In my opinion changing the routing of the wiring harness and making custom fluid lines is your best bet. Its takes less time, A LOT less money and the result is outstanding. I removed everything I didn't use from my harness, ran all new stainless steal lines including, Power steering, coolant, and fuel. I reversed the manifold, put the alternator where the AC condenser was and mounted the coolant tank for the turbo underneath the throttle body. Custom intercooler piping moved everything I could to the other side of the fender aprons (HID, kit, Fuse Box, etc.) Made everything color matched, painted the engine bay gloss black and ended up with a very clean engine bay with the wiring still there. With all the way the engine is made your going to put so much time into wiring and your still going to have a considerable amount of visible wiring, hoses, and accessories attached to you car.
You could also cut the metal out from your frame rails to your strut towers and mount everything farther back and make a cover plate. Same with the fire wall so the crap is still there but itís covered up by a smooth piece of metal. I have done that before. Not to a Subaru but if you good with metal and bad at wiring then that way is for you. I would have done it to my car but I didnít have a welder at the time.