hp compaq 6300 mt pro

I have HP Compaq Pro MicroTower 6300 and Im wonderig can I put 1060 3gb and power it with SATA (Sata to Molex, Molex to 6pin) My rig is: CPU: i5 3570 (77W) GPU: GT 630 2GB OEM PSU: HP (90% eficient I think) 320W HDD: 250 GB SATA 7.2K rmp, 3.5 in (~22W) RAM: 8GB 1666Hz MOTHERBOARD: HP OEM, non...

So, I wanted to upgrade my old PC with a new GPU (GTX 750 1GB Gigabyte), but the problem is that I have HP Compaq 6300 MT Pro, and it has PSU with 320W, GTX 750 need 300W, first I wanted to upgrade PSU but its realy complicated. Only compatible cards are 1050 and 750. I made decision for 750 cuz...