NEED HELP PLOX!!!!

I am constructing a new rig

The proplem i am having is deciding which video cards

The computer

Cpu = AMD Phenom 9950 BLACK EDITION Quad Core 4meg CACHE 2.6Ghz Socket AM2 Retail Box AM2

Ram = KINGSTON Twin Pack HYPER X 4x2 gig (8 gig) DDR2 1066Mhz

Motherboard = ASROCK K10N780SLIX3-WiFi AMD 780 3-Way SLi Dual Channel DDR2 1066Mhz 8Channel HDAudio

Video card = ? dont know ..... I am curious on outhere people opinion . Should i go 4850 x 2 4870 an later add one .... 9600 x3 .... 9800 x 2 if so could you plz state what size powere supply they would require

Ps.... May i also know if the cpu, ram and motherboard are good.

Thx

CPU is okay. Intel is faster.
Ram is okay. OCZ would be better if on the compatibility list.
Motherboard: I like EVGA or ASUS.