Just a quick wattage question.

650W is enough for dual cards, but will leave the PSU running fairly hard under load. 750W is the recommended wattage for dual cards.

What PSU are you looking at?

The TX650 (corsair of course) the TX750 is a good 50 bucks more than the 650, so.

the corsair 650 will be fine

really? are you sure it won't put to much strain on the 650?

Dont think the problem is even wattage, more the fact the TX650 only has two 6+2 PCI-E connectors. A 7870 needs two 6-pins.
There are other good options in the 750W area.

I need the cheapest quality PSU that can hand the 3570k and 2 7870's.

XFX Core edition 750W, 80+ Bronze. $110 ($15 rebate)
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

thanks a ton! interested in seeing the rest of the build/give some advice? I'm not a computer genius, I'm just the most savvy of my friends.

Go ahead and post it, its always good to get feedback on a build.

Okay, here it is:
Case - Cooler Master Storm Enforcer
Mobo - ASRock Z77 full ATX etcetc
PSU - the one you suggested
CPU - i5 3570k
GPU - Radeon 7870 Gigabyte GHz edition (will buy another one later)
HDD - WD Caviar Blue 500GB 7200RPM Drive
CPU cooler - CM Hyper 212 Evo
Optical drive - Asus dvd/cd burner, the standard blah.

Kinda feel like I'm missing something because it's so cheap. (896)

I'll provide links to newegg if you want, it's just that takes alot of tab opening, and the laptop I'm on atm can't handle lots of tabs u.u

Because you are missing something, RAM.  
No SSD? Such a small HDD?

Component choice is fairly good, no issues with it.

Ah, thanks. I'll get the normal old 8GB g skill 1600 1.5v ram. He specified he didn't need more than 500gb of memory to me. Yeah, no ssd. he's on a budget. Also; Damn! Why isn't windows 7 cheaper! >-<

Get an Ares kit if you arent already. Low profile so it wont conflict with a heatsink larger than the EVO if he ever upgrades to a Noctua or something.

You buying an OEM or Retail copy?
An OEM key is around $100 but can only be used on the one machine (the motherboard to be precise). The Retail key can be used on multiple machines but costs a fair bit more (~$230 I think).

even 100 is crazy for W7. now that W8 is out, W7 should be like 40 bucks for oem </3 cx Btw, W8 is the bane of all things desktops.

Have yet to try it myself, so I cant comment on it.
Been trying to download the Release Preview to install on a HDD I have laying around, but it seems to have disappeared from the Internet.

My sister bought a laptop with W8 on it. it's so useless.. It makes me wanna cry cx