You want to run a K-series CPU on a B75 motherboard? either upgrade the MOBO to z77 so you can actually have the capability to overclock your overclockable CPU, or downgrade your CPU to a NON-K chip so the CPU doesn't go to waste. B75 doesn't support overclocking.
or perhaps go to a i5-4670k on a z87/z97 motherboard. I would suggest this route for not much more money at all. You'll get a small boost in performance...but a boost is a boost. Features on the z87/97 motherboards are superior to z77.
also, there is nothing wrong with your power supply. Just MAKE SURE with that one you run TWO INDEPENDENT CABLES to your graphics card from your power supply. Some cables will have a built-in jumper where you can run a single cable from the power supply to dual 8-pin on the GPU, DO NOT use this on your r9-290x with that power supply. This would be fine on some cards with that PSU, but not the 290x. The reason for this is that each 12v rail only supplies 24 amps. If you tried to power the GPU off a single 12v rail instead of dual rails, your PSU would fault and throw itself into protection mode once you loaded that GPU up. You also would run the risk of burning the GPU up. I could run that GPU off a single rail on my power supply to a dual 8-pin r9-290x with a single cable, but I have 70A available on a single 12v Rail.
If I didn't make this clear enough, please ask. The power supply is fine, so don't feel the need to change that for another one.
