nice! you should have a lot of fun with that card. and your powersupply should be fine. I see that power supply has 6 18a 12v rails. if you can find what is on what rail, i'd have 1 8pin/6pin from separate rails to be on the safe side. the 470 according to nvidia's site uses 215watts which is about 18A.
going by this psu
COOLER MASTER Real Power Pro RS-850-EMBAD1-US 850W...
and the formula watts=amps*volts