Obviously, the higher the rpm, the higher the cfm. I don't think you'd stand the sound of a high rpm/cfm fan. There are other ways to cool down a system. Like better case, and case fans.
yes but you'll need powerful speakers to hear anything over that fan. :haha:
personally I'd get a lower RPM fan that's bigger in size(like a 92mm fan), of course you'll need an adapter to fit it to the heatsink. It really cuts the fan noise but keeps the CFM up.