I don't know what games you intend to play... I bought a R9 270x and crossfired with my 7870GHz edtion. Same core on the R9, just a tad bit faster. I don't recommend crossfire solution as it is very very finicky. I would recommend AMD better bang for the buck, and they tend to run cooler than NVidia. Try to find deals on the R9 series on Ebay, a bunch of electronic coin miners are getting rid of their inventory. I got the 270x for $135, in original packaging and the guy offered 30 day money back guarantee.
For example, http://www.ebay.com/itm/Gigabyte-AMD-Radeon-R9-280X-GV-R928XOC-3GD-Rev-2-0-3GB-VRAM-Custom-Mining-BIOS-/251601296052?pt=PCC_Video_TV_Cards&hash=item3a949b1ab4
P.S. Nvidia's stock tanked and I lost a bunch of money so fuck Nvidia. yeah yeah yeah!