CPU = i7-980X (6 cores, 12 CPU threads)
RAM = 24 GB. use 12 Gb for the WOW data files into a ram drive.
GPU = ASUS ENGTX275 or better.
Sound card = some nice Sound Blaster.
Directly buy this one with the CPU and the RAM: http://www.supermicro.es/?opcion=con...%2FSYS-5046A-X
Then ask them to plug the GPU and the sound card, or buy then apart. It's a low noise workstation, so you will be able to hear people screaming better when you blow them with 5 ICommandYouToCorpseRun spells.

Screen = Eizo screen. http://www.eizo.com/global/products/...33w/index.html or http://www.eizo.com/global/products/...31w/index.html.
The screen itself will cost you between 600 and 2k, but it's well worth the money, specially knowing that you can buy a new screen but you cannot buy new set of eyes.
I have this one http://www.eizo.com/global/products/...02w/index.html . Compared to my ViewSonic, Sony, Samsung and Dell screens, it completely blows them apart. I have choosen that exact model because it has fast response time and lower power consumption.

Put the HDs you want, the data files into RAM will be faster than any SSD HD, so I would go for two SSD, one for the system and one for gaming and the other HDs for storage would be WD green series 1 or 2 TB drives to store all the porn.

With the Supermicro workstation + the Eizo screen you will probably have to put a bit of extra money to get it all set, but it will be a killer rig.