Question about GTX780 surround..

Selo1

Honorable
May 17, 2013
28
0
10,540
Hey guys, I'm building PC for my friend and I'd like to ask something.. The system is GTX 780 Ti with i7 4770k and 3 monitors. And I want to add second card as dedicated PhysX card I was thinking about GTX 760 or 660 Ti.. 780 Ti is made by Asus and would it be a problem if the second card is another brand? Let me know what do you think would be best? (Sorry for my English).