I didn't mean to imply that the 750W would be needed, just that those were the only Coolmax brand psus that were considered any good. 500W from a tier 1, 2, or 3 product line should be fine, unless there are other considerations.
I also just noticed that the OP selected an A6-6400K cpu, which requires socket FM2, while the motherboard linked is socket AM3+, so those won't work together.
Edit: Matrix890, the incompatibilities might be why you couldn't find many of the components desired on pcpartpicker, since the compatibility filter would have hidden them.
Why don't you fill in a copy of the template:
http://www.tomshardware.com/forum/353572-31-build-upgrade-advice
Then we can help you better with component choice.