It is physically impossible to get 10C temperatures unless you are in a room that is @ 10C. This holds true for water cooling as well.
I know it may seem logical, because to most people: fans= cool air, but fans only cool us off as they allow for the quicker evaporation of sweat. However, if you're room is @ 20C, the air is still going to be @ 20C, no matter how much air you're putting out.
QFT. Below ambient temperature is impossible with air or water cooling. Only under dry-ice etc can taht be achieved.
For core temps, just use PCWizard, Everest, or HWmonitor is a good one if you don't want a big download.
As you have a Black Edition CPU, it has an unlocked multiplier. So instead of increasing the HT bus, you can easily overclock just the CPU using the multiplier. Bus speed is 200MHz, every increase of 1 on the multiplier increases the clock speed by 200MHz.
If you lose stability, simply give the core voltage a small jump and test again.
Once you've accomplished that, you could try increasing the NB clock to gain a little extra performance, just make sure your RAM stays in spec though.
Once you're a little more experienced, you could try decreasing the multiplier, and raising the HT bus speed to see if that makes a difference to performance.