The case speaker should not be a big issue>
http://www.bestbyteinc.com/CAS-CHW-SP1.html
If you use a fan controller to control fan speed when not gaming it will quiet down.
http://www.newegg.com/Product/Produc...82E16811998065
The noise comes from the fans the quieter the case the less air flow for the most part.
This is one of the quietest case but as you'll see from the reviews there are complaints about low fan speeds and temps >
http://www.newegg.com/Product/Produc...82E16811119192