Not sure what the 80mm fans are for, or where they would go. There are not places in the case that won't be filled with the 120mm you listed. Certainly room for one in the back, but that is also a 120mm mount.
CPU cooler is adequate, but not ideal for overclocking. 970 or 990FX chipset on the motherboard is also recommended for overclocking, if you plan on that at all.
You'll want to stick with the 2x4GB kit.
No need for a 4GB video card with that monitor resolution.