1. 650w gold psu will do for non SLI 770gtx
2. Depends on how much you want to overclock that precious of yours. 4.9Ghz i7 4770k reached 100°C on water cooling and I thought Corsair H100 is cool. For mild overclock I think it's good enough that Phantek.
3. UD3H got a better audio chip and an extra fan header. The other options are just for extreme/pro overclocker (onboard power, reset and clear cmos buttons, voltage measurement points and dual BIOS switch).