Dust will make anything create more heat because it restricts airflow. Every six months or so, depending on how dusty your house, take a can of compressed air to everything. I have seen so many systems practically choked to death because nobody bothered to do proper maintenance to the hardware. The cooler I have, that I linked, has not let me down. I had it for awhile on my core i5 750 and is now on my i5 3570k. Due to my ram height, I have to slide the fan up a bit to install and remove memory. The fan slides down pretty much on top of it. If going corsair, I would go with their XMS as the heatsinks are shorter. I recently built a system with Crucial Ballistix and had no cooler issues there either. Microcenter doesn't sell Gskill yet, sadly. Gskill's Ares line is designed to not interfere with high end coolers due to heatsink height. I am a fan of the Gskill Ripjaws though. That is what all my desktops are currently using. Now that I think about it, I even have an 8gb Gskill ddr3 kit in my laptop too. Bought it for $30 last year on black friday.

 

Also, if you go with a solid $150 or so motherboard, you can take the money saved over the more expensive one and spend more money on an even faster graphics card.