Upgrading my system, What should I buy?

[dissevered]

Currently I am using

16 GB Ram
120 SSD
2TB HD
970 MSI Motherboard
AMD Fx 8150
660 TI
a 6 year old 1000 watt power supply ( cables messy, should I buy a new one?)

I currently have $650 to spend on upgrades and can get more money if needed.
I want to upgrade my Graphics Card for sure since its Phys X component crashes often( I have to disable it). I am thinking of getting a Nvidia 970, this leaves me with $300 left to spend if I want to spend it (I definitely want to spend it upgrading my pc in the end, but might consider saving up for something better)... also unsure if 970 is the graphics I want to be getting

Computer is used solely for gaming/streaming.

I mostly play League, but also RPGs like Far Cry 4, Inquisition, and future games.

 

[clutchc]

Add a i5-4690K and a Z97 MB to the GTX 970.
What PSU is it... make/model?

 

[dissevered]

Add a i5-4690K and a Z97 MB to the GTX 970.
What PSU is it... make/model?

I don't have my pc with me atm, but its unknown brand. I am unsure if the power supply hinders my performance ( it shouldnt afaik).

Since I don't have the money to upgrade the cpu atm, I can buy a new power supply since I really dislike the wiring. How much power should I go for? 750?

 

[clutchc]

750W? You don't need that much for the 125W CPU and 145W gfx card. You would if you ever added a 2nd card, tho. But that will depend on which model MSI 970 MB you have.
If you stay with a single card, any high quality 600W or better PSU will be fine. Even a 550W would do, but there wouldn't be as much headroom available... something I always like to have. Here is a tiered PSU list to use as a guide for picking a good PSU: https://community.newegg.com/eggxpert/computer_hardware/f/135081/t/45344.aspx?Redirected=true

The reason I suggested the CPU/MB combo, was that many times retailers will offer a nice i5/Z97 package at a reduced price when bought together. And since you said you had ~$300 to spend, it might just be possible to get them for that price if you search.