Well I'm from Greece so these to options are way over my budget. For example the corsair TX750 is an option for me as it costs 110euros or 150$.(If I am to spend a little more). The one you suggested costs 140euros. Also do I really nead the 750W?
750w is needed for your SLI.
The TX750 would be fine.
I'm not really planning on putting another gpu, will 650W be enough? If i ever put another gpu, I'll upgrade again.