Yes your PSU will work fine. It is more than enough wattage.
Unless you feel like you may need extra headroom in the future (for example, adding another graphics card), 750 Watts is fine.
Well..... It is mostly built already. I'm just finishing cable management and today at work someone told me I need at least 850W. I just spent $500 on the GTX 780 so if I add another graphics card I could just plan on upgrading the PSU then. You are all confident that I wont damage anything from mal-power?