So I just spent 2 bloody hours doin cable management and made a complete hash of it lol, though on the plus side I put the USB and rear exhaust fan wires under the mobo and out of the way
Before:
http://img.techpowerup.org/090518/Image2340.jpg
After:
http://img.techpowerup.org/090518/Image2346521.jpg
I should have left the DVD drive up the top...
I hate IDE and I hate Molex lol. I'm assuming a SATA optical drive uses SATA power connections? lol
Yes it will...but the SATA power aren't much prettier...but it does help to have all the drives clustered since the SATA power plugs from the PSU are usually a few inches from each other on the cabling.
I got a 900 when they first came out and my first attempt was pretty much the same as yours. Then I made a nice round hole in the mobo tray/panel right beside the PSU right where the cabling comes out of the PSU housing. A hole just large enough to fit the 24pin plug through sideways...
Then I made a hole the size of the PSU fan right where that would be on the case bottom panel if I flipped the PSU. I put some tall case feet on the bottom for ventilation. Now all of the wires from the PSU just route through that hole.
Obviously you will need a few other holes strategically placed. This is easy to do by tracing the mobo edge with a pencil (lightly so it wipes right off later) and then making tic marks where the 24 Pin, 8 pin, sata leads and any other cabling needs acces. The hole should split the line traced around the mobo so it is half hidden. Route the cables first then install the mobo. You will still have wiggle room.
I line the holes with thin grommets or strips of small c-channel but other people use electrical tape or you can just sand the hole until it is no longer sharp and use nothing. By planning out the "layers" of cables coming out the back of the mobo panel you can use nylon conduit clamps and secure them with screws into un used threaded holes or make your own. Or use tape or cable ties.
Go for it man