kaa992 :
Do you recommend anything? I got a couple 500w PSU's but I dont know if they have the right cables.
If they are good quality 500W PSUs (not cheap, junk fake 500W units), one of them will be fine for the GTX 960. But like you say, some 960s will require a single 6 pin, some an 8 pin. It will depend on which card you get.
But any 500W PSU that is NOT junk, will have those cables. If yours don't, it isn't a real 500W unit. Or a very, very old unit.