IndraS :
its asus
and then which psu should i use?\
What is an "asus nvidia gt"? Is it a GeForce GT 645 (OEM), GeForce GT 640 (Retail), GeForce GT 640 (OEM) with 128-bit GDDR5, GeForce GT 640 (OEM) 192-bit DDR3, GeForce GT 640 (OEM) with 128-bit DDR3, GeForce GT 630 (Retail), GeForce GT 630 (OEM), GeForce GT 620 (Retail), GeForce GT 620 (OEM), GeForce GT 610 (Retail), GeForce 605 (OEM), GeForce GT 520, GeForce 510 (OEM), ..., etc.
What PSU brands and models do you have available for purchase? Do you have a link to an online vendor that you deal with?