What Mainboard are you using ?
I have a ga-z68x-ud3h-b3. Only the cpu-fan and the system-fan can be controlled. One thing I forgot to mention is that the reason I am going for this solution is that, when I am on my desktop the fans run a little too fast (and make a little too much noise). When gaming, they might be running a little too slow since I tend to overclock stuff (also when it isn't needed, just because I can ;) ).
So basically the solution I mentioned in the OP seems to be the best one. 120mm PWN fans aren't hard to find or expensive, 140mm on the other hand are a different story. I need the 140mm's because that’s the only size that can be fitted in the roof of my case. Here is possible
140mm fans I could use. The thermalright has good reviews, but also has 120mm mounts, so a no go. To me the best option seems to be the Be Quite! one. What do you guys think?