Hi,
I just installed the Ninja Plus rev 3 on my MSI K9N Neo V3 motherboard (in an antec P182 case).
The coler fits perfectly. It does reach over the two left most dimm slots, but the cooler is high enough so that, if you put dimms in that slot, you still have a good 1cm clearance.
Of course, dimms with large heat fins on them probably wont fit.
I took some pictures (with my not so good phone camera) and put them online:
Index of /Ninja
Do note I am using the Ninja in fanless mode, but there would be no problem to add the fan to the cooler if it is needed.
If you want any other info, please pm me since I am not a regular visitor on this forum.
wkr,
Jhon