Why exactly do you recommend only 1 video card? Wouldnt 2 cards help on the performance? Lets say I open 2 WoW windows on each card.

So the list is as followed:

619272 - Intel Core™ i7 Quad Processor i7-2600K 3,4GHz, Socket LGA1155, 8MB, Boxed
626388 - ASUS Sabertooth P67, Socket-1155 ATX, P67, DDR3, 2xPCIe(2.0)x16, CFX& SLI, SATA 6Gb/s, USB 3.0, FW, BT, EFI
618010 - Corsair Vengeance™ DDR3 1600MHz 8GB CL9 Kit w/2x 4GB XMS3 modules, CL9-9-9-24, 1.5V, Vengeance Heatspreader, 240 pin

Crucial m4 SSD 2,5" 64GB

Corsair Vengeance DDR3 1600MHz 8GB CL9

2 x Gainward GeForce GTX 570 1280MB or 2 x Gainward GeForce GTX 560Ti 1GB
VS
Gigabyte GeForce GTX 580 3072MB PhysX



Why exactly do you recommend only 1 video card? Wouldnt 2 cards help on the performance? Lets say I open 2 WoW windows on each card. Wouldnt WoW run smoother on each client? And if so, should I go for the 570? or go for the 560?

Another question, what will a SSD bring to the table? Im only looking for a smoother gameplay in crowded areas, less laggy arenas etc.