Re: Gaming desktop.
I disagree with... everything Lipzo said tbh xD
1. The Phenom II x4 995 is on par with at i5 2500k any day if you ask me, generally the performance stats would be impossible to tell between and one costs a bill less than the other. Either way to 1055T pulls down it's pants and does a sloppy poo all over the 2500k.
2. Depending on how much you're overclocking by, stock cooler may be able to handle it. If not, get a Freezer Pro, dirt cheap and does the job as-good-as it's premium rivals.
3. go with MOAR RAM AND/OR faster RAM. I'd recommend atleast 6GB to go with your chip, since i guess you'd use x64 Windows. Your board supports up to 1800 (so a site i just googled to says) so you could look at Dominator RAM if money is no object. Look into Corsair Vengeance as it's a nice compromise at 1600. As far as i know it only comes in a 6GB kit as triple channel, so im going to go ahead and recommend the 8GB dual channel kit.
4. For WoW/SC2, a 1GB card will be fine. GPU memory basically just dictates how much 'graphics stuff' can be displayed at one time, and how well (obviously also depending on the particular graphics chip, in your case the AMD 5870 chip). Generally, i say to customers that the moar monitors/bigger res you have, the more memory you should look at for your GPU. E.g. if you're using 3 monitors in Eyefinity or NVIDIA 3d Vision Surround, then more memory is a good idea.
Anyway, i really doubt you'll ever feel the need to overclock that chip, unless you have some serious chip ego or something. Another thing you also should consider is a case with adequate cooling/airflow properties. the Antec 300 Three Hundred is a good mid-end case for gaming PCs.
EVGA SLI Micro Z68 // Intel i5-2500k // 8GB Corsair Vengeance 1866MHz // Overclocked 2GB MSI R9 270X // Corsair Carbide SPEC-03 // Kingston Hyper-X 120GB // 2TB WD Green + 500GB WD Black