Scythe Ninja B. or Thermalright ultra 120 or Extreme

I was wondering which is a better buy. I hear they all cool well, but how is the setup for each. Is the ninja harder to mount or is the Ultra 120 easier? I am leaning towards the Ninja because it is cheaper atm, but ya what do u guys think?

The Ninja B is $35.95
http://jab-tech.com/Scythe-NINJA-PLUS-Rev.B-6-Heat-Pipes-CPU-Cooler-pr-3538.html

Ultra 120 is $45.95
http://jab-tech.com/Thermalright-Ultra-120-Heatsink-pr-3406.html

Ultra 120 Extreme is $59.95
http://www.jab-tech.com/Thermalright-Ultra-120-eXtreme-pr-3762.html

I was thinking of replacing the fans as well atm I have
Scythe S-Flex Fan - SFF21F. Do U recommend a different fan or stay with it.

http://jab-tech.com/Scythe-S-Flex-Fan-SFF21F-pr-3257.html.