On 2010.05.05 -> lowered CPU Vcore = 1.09375 and Vtt = 1.170. Everything works flawlessly and on 2010.06.01 I am absolutely sure that my system is 100% stable, I didn't get any single crash or problem in this time.
I posted the latest config at CPU-Z validator http://valid.canardpc.com/show_oc.php?id=1219013
As for noise, the four 12 cm vents (two intake on front of the case and two exhaust - one on back of the case and one on power supply) do a wonderful job in keeping the system very well cooled and surprisingly quiet. CPU cooler is very silent as well; the loudest components are by far the 3 HDD's and the video card when I play 3D games. Overall the system is fairly quiet for my taste, and under the desk where i keep it is totally not disturbing.
I am planning to keep this computer with these settings a very long time from now on, and I am very happy to have found the perfect overclock for me after all the tests and tries.