sounds like that should get you a nice case, an
i7 2600k ( or a lower model if you want)
a radeon 6970, (asus make good graphics cards, so do sapphire. XFX are cheap with double lifetime warranty.)
(6950/6870 if you want to save money for lower performance) (Geforce 560ti/570/580 if you want to go that route, but they are more expensive)
an z68 socket 1155 motherboard. (asus make good motherboards, gigabyte and msi are also reputable.)
(look for ones with multiple PCI-e slots and maybe a couple of PCI slots, although these are mostly useless now.)
Corsair and seasonic make very good powersupplies, i would suggest the 700-1000w area (the higher graphics cards are power hogs, and a 850w+ psu will be able to give you room to upgrade if you want to.
RAM is something that doesnt really matter how much you spend on speed, just as long as you get DDR3. 8GB of ram will do fine, Corsair are a good brand. Get their vengance line if you want to spend on speed.
western digital make good hard drives, their 7200rmp 2tb drive will do fine.
(you could also spend money on an SSD if you have cash left over, samsung, OCZ, intel (Although intel are expensive.)
wifi cards arent a big thing to get worked up over if you buy them.
buy a good, big tower case. they are easy(er) to build in.
dont forget to add mouse,keyboard and monitor into the price (although i think you mentioned central unit, so does that mean you already have those)
