[build help] want to upgrade graphics card

im looking to upgrade from dual gtx 465s in sli and im wondering what my best option would be. my rooms getting quite hot with the running games so im looking for performance with little heat.

i hear the 7850s are good as is the gtx 670. will a single 7850 bring down my performance? is the gtx 670 prices justified? i'd like to hear from build a pcs community.

im currently running games off of a crucial m4 ssd and running a 960t zosma oc'ed at 4.0 ghz. using a 750 watt psu and i think my power consumption on the 465s is using too much power and my pc locks up when i unlock my proc to a hex. it was stable before with just one gtx 465.