i recomend a little guy called the search function. im not going to do your work for you but i know for a fact ive seen a dozen of these ds3 northbridge threads in the last 10 or so pages of posts.
I replaced the nb cooler on my MSI p6n sli-fi with the active nb heatsink/fan from my dfi ultra-d motherboard (the holes were the same and it fit perfectly). So, assuming that the hole placements are standard you could probably go with one from that site. Worth a look anyway.