Can I use only one 780Ti and add another one in the future? (I guess I need better PSU)
Can I add more/ replace to a faster ram in the future?
Can I replace the cpu in the future? (without replace the motherboard and PSU)
Does the gpu and cpu Coolers are good enough for OC?
I would prefer it will be 2000 dollars with keyboard, Monitor, mouse and Win 8.1 OS.