Ok, so right now I have a crappy computer that has managed to run 4 wows in 1700 bracket last season.. I am needed more power If I play Wrath.. (back from a break,, but i have a 80 already) i have my shaman group at 72,but i need more power..
As for upgrades, I plan on upgrading my CPU, RAM, videocard, Motherboard, what else do I need to fully upgrade my system? i know power, (please tell me what power I need for these upgrade specificatoins.

CPU- Intel Core i7 920 2.66GHz 8M L3 Cache 4.8GT/sec QPI Hyper-Threading Turbo Boost LGA1366 Processor
RAM- Corsair TR3X6G1333C9 XMS3 6 GB 3 x 2 GB PC3-10666 1333MHz 240-Pin DDR3 Core i7 Memory Kit
Videocard- I am not sure what is really needed for a videocard, other than making it look nice, does a videocard actually make the movement smoother? or is there just more detail? I want something that looks nice and will run smoothly.. not really sure.. maybe a raedon?
Motherboard- Intel DX58SO Extreme Series X58 ATX Tri-Channel DDR3 16GB SLI or CrossFireX LGA1366 Overclocking Utility Desktop Board
Cooling/power- how in the would I know how much power and cooling i need for these 4 upgrades? also is there anything else?

Should I might as well buy a new computer? thanks

This is my system specifications