I am getting dual msi gtx 760 4gb and a corsair cx750 psu and i am wondering if i will have enough cables and openings on the psu for those cards, i think they both each take an 8pin and a 6pin
Based on this: http://pcpartpicker.com/p/gBhfhM , they should be compatible. It looks like the card itself comes with a 6 and 8 pin power adapter. Your PSU has more than enough power for these two cards, and has the correct cables.
Yes it would have enough cables for dual 760s but I would recommend you get a different PSU. The corsair CX series uses cheap chinese capacitors and I have seen a lot of posts on the forum with people that had problems with them. Try to get this one: