Hi everyone, looking to possible bring my computer up to snuff for WoD. Here is my current build:

i7-2600K
Radeon HD6870 1GB
8GB ram
128GB Vertex2 SSD
1TB WD HD
750W Power Supply (Corsair I believe)

Thinking my video card needs the upgrade, but not sure what I can grab without having to upgrade CPU and Motherboard. Also I may want to try Crossfire or SLI to see if that is a big performance boost. have PCIex16 2.1 if that helps. Budget wise I could probably afford to build a new computer ($1500-2000) but want to just see if I can just max out what I have to play WoD at a high level. Thanks in advance.