Two diffrent version of the same GPU in SLI

My current GPU is a EVGA 03G-P4-2782-KR GTX 780. I want to upgrade my rig by getting another GTX 780 and putting it in SLI with my current GPU. Do I have to use the same modle or can I use any version of a GTX 780? 

As always, thank you

You can use any model of GTX 780. The cards will adopt the clock speed of the lowest performing card.

It depends, they usually need to be almost perfectly identical as in same GPU architecture and same RAM size. I don't remember if they need to be the same clock or not, I doubt it. Nvidia is very restrictive on what can and can't SLI so I would play it safe and get it from the same manufacturer but I think you can buy one with different clock and be ok

You can choose any model of GTX 780 to SLI with your EVGA 780. Just make sure to get the same amount of VRAM on each GPU for best results.