you will get 2 cables with the motherboard. As long as you only install 1 HDD and 1 DVD drive, you will be fine. Most other things that need cables come with them.
that looks pretty good, and if this has been said before sorry, i haven't read the rest, but you know you only need 650w max for that, are you planning to go crossfire later cuz otherwise i'd drop the watts.
Nothing wrong with using the HX-750 at all. Better to have overhead for the future, then upgrading your power supply over and over. I would probably get a good set of G Skill memory over the Corsair. Plus havent had nothing but problems with LiteOn drives, alot of tray belts breaking.