Noone is going to be able to give you precise settings to do what you want. Don't get me wrong - they'll get you darn close but all chips are not equal. At the end of the day you'll just need to take your time and tune settings one after another, stress test, tweak, stress test, etc.
I would start my voltages low and work your way up until you can post, stress test. Then it might fail 8 minutes in, bump it up. it might fail 1 hour in, bump it up, no fail for 12 hours and you're probably good. Then you can start playing with your RAM.
You should def be able to do better than 3ghz. You won't fry it just watch your temps that's all. Those chips are tougher than you're giving them credit for.
I see what your saying and noticed from your profile you lowered your multi to 8x to get a higher fsb and was wondering why you did this and what your multiplier was set at?
Also is the best way to overclock the nvidia 8800 series to just use the ATI Tool?