READ THIS for the mobo:http://www.tomshardware.com/reviews/usb-3.0-sata-6gb,2583.html
Before the ram and GPU questions can be answered, what are you using this rig for? And no matter what the answer is, 9gb or ram is not the way to go.
Thanks to all for ansewring. I will be using the i7-860 mainly for for graphics, video, and some scientific processing. I am already set on LGA1156 socket, quad core, hyperthreading, Dual Channel DDR3, USB 3/0, and the chipset P55.
I have began looking at motherboards from ASUS (P7P55D-E Deluxe, Evo, Pro, LX) and Gigabyte (P55A-UD7) that have the USB 3.0 specification, but I began to realize that I have too many doubts and that I better consult with people that know the technical stuff.