Alienware Aurora R1 Cannot add sound card

Guys I need help to figure out how I can install my Asus Xonar ROG Phoebus Sound Card into my Alienware Aurora R1.

The problem is i have no more 6-pin head cable available to connect it to the sound card since I used 2 6-pin head cable for my VGA GTX 660 Ti. 

Is there any way for me to get an extra 6-pin head cable in my Alienware Aurora R1 without switching out the power supply? I cant get dell to send them a 875W PSU into my country since it would cost so much.

Or are there any other PSU that will fit into the alienware aurora casing?

My current PSU is 525W