I built my first pc about a month ago and in the future, probably about christmas, i may look into crossfiring my build. I have an i5 4690k cpu, and my gpu is the sapphire r9 280x. As far as i know at the moment, i think i can use a variety of gpus to crossfire with, not just r9 280x. Basically i just want to know if the best gpu to get with my setup, would it be another r9 280x, or is the hd 7900 series better to get?