like i say, a re-organisation of the room sounds in order.

maybe the pc/xbox under or to the side of the screen,along with sub and centre speaker,and the other speakers elsewhere,with a longer cable from front to back of room, to connect the xbox/pc to the pj.
sounds more feasable than where you have it at the moment,what with your new systems styling(centre speaker integrated,etc).
mine is all near/under my screen,with a 12 metre hdmi cable from front of room to back,connecting it all to the pj.