Need help with CPU Fan and cooling

Hi all, I just recently build a wonderful PC with the help of people from this Forum.

This is what I have:

CPU: AMD Phenom II X4 955 BE, currently using sock fan.
Motherboard: Gigabyte GA-890GPA-UD3H
Power Supply: Corsair CMPSU-750TX
RAM: G.Skill Ripjaws Series 4GB DDR3 1600
Hard Drive: Seagate Barracuda 7200.12 500GB 7200 RPM SATA 3.0Gb/s
DVDRW: SAMSUNG CD/DVD Burner

I looking into a few fans.

1) Hyper 212 Plus, read that it is too big, and it can get too close to RAM. Is this true? Also, read that it is not sufficient to run at higher loads.

2) Zalman CNPS10X, a bit expensive, but got a few good reviews. No one has mentioned about space problems with this one. Does anyone got reviews for this Cooler?

3) Can anyone suggest a good CPU Fan that is extremely quiet? I won't be doing any Overclocking, even if I do, probably not that intense.

Also, is it necessary to add Case Fans for extra Cooling? If yes, can anyone suggests quiet case fans?

Thank you all