Speaker positioning on dedicated room

I am building a dedicated room on my new home (home is already built so I am stuck with a semi square room), I am in the process of redoing the floors, so I would like to leave pipes under the floor to route speaker wires from the rack to the speakers, and then also route the wires for the proyector to the rack through the ceiling.
I have already designed my idea, here I leave the picture:

http://img80.imageshack.us/i/roomfc.jpg/

Can you tell me what you think about this positioning? I did it basing on the cardas room setup guide.

I can later move the speakers around a bit, but I need a starting guideline for placing the pipes.....the idea is to keep the cable runs as short as possible (that is why I want to route them under the floor)

Any input is highly appreciated! The speakers are B&W 803D, amps is a W4S, the system is stereo although I will have a proyector for watching blu ray discs. The room will have acoustic treament on ceiling, walls, floor will be thick carpet.

Thanks!
Demian