I have a similar build to yours CPU and GPU wise:
-i5 4460 3.20GHz
-MSI GTX 970 4GB
-Corsair Vengeance DDR3 1600Mhz 2x4GB Dual Channel 8GB kit
-1920x1080 LG monitor
-EVGA G2 550w Gold Modular PSU
-Samsung EVO 850 250GB SSD
-1TB WCD Hard drive
-ASRock Z97 Anniversary Motherboard (Socket 1150)
-Windows 7 Home Premium
I just recently replaced my old gagging Corsair CX 500w Bronze and it was worth it. Also I have some extra watts with my new one.
A GTX 970 is recommended to have a 500W PSU powering it,
always try and go above the recommend wattage slightly if you can.
Also you will need a PSU that has a 6 pin and 8 pin connector as the MSI GTX 970 requires one 6 pin and one 8 pin PCIE power connector plugged into it to run.
Both...