You could use your existing hard drive if you wanted to save on costs. Wait until the prices get back to normal to upgrade or add a second drive. Adding a second HD 6870 in CF will have power consumption below 550w so the XFX 650w has plenty of power. You WILL need to overclock the CPU (or any AMD CPU for that matter) to do its best to keep up with a single, or dual, HD 6870 GPU.
CPU Cooler - You could do without the Hyper 212+, or other aftermarket cooler, but your overclocking would be seriously limited. With the Hyper, or similar cooler, you can expect 4.0~GHz on a stable overclock. With the stock cooler you are going to hit thermal limits well below that.
MEM - Good modules, but the tall heat spreaders could cause clearance issues with an aftermarket CPU Cooler. The Hyper 212+ might be ok, but it is best to get standard height / low profile modules. There are a lot of options out there. The Corsair XMS or XMS3 modules are good options. ...or the GSkill Value series.
PSU - Either of those would be fine. Corsair and XFX both make quality power supplies. If you are debating on adding a second HD 6850 later then I would say go with the 650w now just for peace of mind, but in all reality a good 600w unit would will handle two HD 6850 GPUs. Personally I like to go a size or two larger for effeciency sake...
Case - That Xigmatek will be fine. That is all personal preference and what fits in your budget. I like the Elite 430 for its stock fans and good cooling. Nothing special past that...
I built a $620 PC which included a 6870, i3 2100, 23" Acer monitor and a 250GB HDD.
Since you already have an HDD, an i5 2400 and a 6950 shouldn't be much of a problem at your budget. Look into a mobo in the $60-70 range since it's usually a waste of money at this price point. Don't CF at this price point man, it's stupid IMO. A 500W PSU with the 6950 should be fine. Antec Earthwatts, Corsair, Seasonic, OCZ PSUs are recommended pretty often.
BTW, PC parts are pretty cheap in Germany/Poland from what I've seen, if you know where to look. I've seen a 5850 for 500zl = $156. I don't think this is very relevent, but it's possibly worth mentioning I guess.
6950 is probably to high i dont want to waste money on that cuz i havnt bought my monitor yet. So a hd 6850 or gtx 460 is more than enough for new games. Also i5 2400 :S better 2500k cuz it can be Oc-ed thats why i chosed AMD X4 960T -> Unlocked X6 1600T @ 4 Ghz 1.83V Air cool stock max 47C . I can get this parts even cheaper !
@fatfatr i didnt want to Cf or SLI right now but in later future so a 500-600W PSU is enough.Its hard deciding on mobo thats why i asked help! I have already 4 x 40 Gb hdd sata = 160 Gb and its enough till HDD prices drop.I3 2100 is a dual core and its not as good as 960T with 4-6 cores(refering to gaming and multitasking).My current monitor is a 1280*1024 till i buy a new one 720-1080p.
thats why i chosed AMD X4 960T -> Unlocked X6 1600T @ 4 Ghz 1.83V Air cool stock max 47C .
If you are at 1.83v there is no way your temps would be 47C after running Prime95 for any lenght of time. I would guess that is a typo... You should be closer to 1.4v to hit 4.0GHz. Anything above 1.5v is just asking for trouble...
In that case i3 2100 or Phenom II x4/6870. Should be do-able cheaper. I wouldn't settle with less than a 6870 though. The stock Phenom cooler is decent, although the Hyper 212+ would be worth it though if you manage to get 4.0Ghz or more.
Well what I meant is that if you buy the Phenom II x4 you're stuck with AMDs flagship quad core CPU. Which means you won't be able to get a worthwile upgrade until AMD releases some beefier CPUs to compete with Intel, or until you buy an LGA socket motherboard.
Gaming will be main purpose of this build. But not only cuz i do alot of multitasking ! Watching movies while utorrent open and converting videos to.Surfing in the internet with lots of pages opened and ofc i want a fast and responding system So who wins ? D: