If it's just for gaming, drop the i7 and buy a i5-4690K, it's a waste of money. Gaming does not need 8-threads.
Yes, change that PSU. Get one from EVGA, Antec or XFX 80+ certified, 550W at least, the GTX 970 doesn't need too much.
Optional, buy a 240GB (at least) SSD for your system.