You could use Cooler master's Vortex plushttp://www.newegg.com/Product/Product.aspx?Item=N82E16835103084&Tpk=vortex%20plus
I have this in my case (I bought it because I would not have to remove the air duct to my side vent on my case). They list the dimensions in metric, but it only sticks out 3.3" based on what the box says. The one side edge can come very close to being over your first RAM slot so if you have a tall heat spreader on your RAM it might not work. I am using corsair XMS2 for my RAM and I have no issues but the heat spreader is basically no taller then the RAM.
Also like some say it is best to do a dry run on the install to see how it goes in as it is a bit finicky.
Here is a reasonable review written on it: http://www.frostytech.com/articleview.cfm?articleID=2522
I use it on my Phenom II x3 740. I have my Volts at 1.5V to get my OC (under load from Prime 95 it hits about 60C in a somewhat warm room (or in the winter it is more like 55C). I just checked this is 35C above ambient temps. I don't remember the specifics but on my athlon X2 6000+ at stock I know it was for sure cooler then the stock fan stock.