Triple channel kits are for LGA1366. You will need a dual channel kit and 4gb is plenty for gaming. You can always add another 4gb kit later when needed. Video editing and 3d rendering would need more ram.
oh its a mobo, what difference does it make? if ive got 4 ram ports that can all support my ram?
wait, do all ram ports support 1333?
You have a option of setting your ram up in dual channel with a equal amount of same size sticks per channel. (you have two) This will be faster than more ram in single channel which will happen with 1 or 3 sticks installed. Your motherboard supports 1333MHz
6 cores alone will not help with gaming. There is only X6 1100T that is faster than the 955BE so X4 is the better choice. The 955BE can easily reach the speed of the 965BE with a simple increase in multiplier. Only if you have 2 or 4 sticks will the ram run in dual channel the 3 stick will put all the ram in single channel.