If you ever want sli you will need a dual gpu card for that motherboard (2 gpu's, one card).
CPU voltage, I wouldn't leave auto but try 1.36V that should be plenty. It is a G0 stepping? Get cpu-z and check that, if the multiplier in it says 6x and about 1.6Ghz clockspeed, just ignore that it is just intel speedstep to save power, it will run 2.4Ghz stock once loaded, same will go for 3Ghz.
I would run prime95 or OCCT for about 1 hour to test stability minimum, 4 hours or more is generally better and will tell you if it is really stable. So try that and post back, if it doesn't work don't worry there are plenty of things which can help.