This CANADIAN link is well sorted with reviews to help you decide:http://www.ncix.com/products/index.php?minorcatid=1023&subminorcatid=138
1) ensure the FAN can be speed controlled by your motherboard. Your motherboard will either support 3-pin via VOLTAGE, or 4-pin via PWM. (a 3-pin can fit in a 4-pin but you can't control the speed).
So look at your motherboard manual. There will be BIOS settings related to fan speed control as well as a software application for the motherboard (support site).
2) RAM heatsink clearance as mentioned.
3) Google REVIEWS.