I've got it at 1.45v now. I'm giving serious thought to going with the 790FX-UD5P as well along with the Phenom II 940 BE.
I used Durch's official AM2 overclocking guide. The mobo isolation phase I got the reference clock to go to 395 MHz with the HT at 4x. In the processor isolation phase I could only get the reference clock to 230 MHz with the multiplier at default (13.5.) The memory isolation phase I had the best results with 4/4/4/12/22 timing. I got that stable with a reference of 232 MHz with the multiplier at 10x. I don't have the info in front of me, but it put the stable memory speed at somewhere around 470 MHz.
As you can see from my title I am an overclocker in training and no expert on any of this. Any advice would be much appreciated. I already got some in my "new member" post, but I'm at work so I can't try it.