Which psu for dual HD 5970?

Yes. See also:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

The second is modular.

My friend is running his Core i7 980X, 12GB DDR3 memory, 3 hard drive and two 5970s with a 1000W corsair.

On another note, if you haven't already purchased the 5970s, get three 5870s instead. Performs identical and in some cases, better at a lower cost:
http://www.hardware.info/nl-NL/articles/amdnampoZGCa/Cl...
http://www.hardware.info/nl-NL/articles/amdnampoZGCa/Cl...
http://www.hardware.info/nl-NL/articles/amdnampoZGCa/Cl...

850W is enough but get a quality 1000W unit and you'll be fine.
http://www.newegg.com/Product/Productcompare.aspx?Submi...

No I haven't gotten the 5970's yet. I thought they were "it" ;-)
Guess I'll consider dual 5870's, but can it handle 3 or more monitors for Eyefinity?

I have an i7-930, 6GB DDR3 (Mushkin Redline...was thinking about getting more, but not sure), but I am able to get that Sparkle for about $275, but maybe I should just for that Corsair 850? I was reading on Newegg that the Corsair 1000 was setting some computers on fire or frying out the components! Weird...

enermax revolutions 1050w would be a good option

Anything above a good quality 800W PSU is a waste of money, unless you desire to add another card later...

A single 5870 can handle 3-monitor Eyeinfinity. 2x would just be faster...

^ yep and 3, like I suggested, would be even faster, but 4 returns virtually nothing.

1) Buy 2 5870s and call it a day, eyefinity with more than 2 GPUs is total BS, just google for it and see! I have 1 5870 1GB and I play many (but not all) games smoothly with max settings @ 5992x1080 (5670x1080 after bezel correction). If you have the money, buy 2 of the 2GB versions of the 5870, the added vRAM will help in eyefinity resolutions. See the review on WSGF.
Another option is 2 Geforce 460 1GB in SLI and hooking up 3 monitors to them (2d vision surround), they're much cheaper than the 5870s, and offer more bang for the buck.

2) 6GB of system ram is more than enough. If you want to add more ram, make sure to buy the same kit and that they don't run faster than 1333mhz, as most mobos will have trouble running 6 ram dimms @> 1333mhz.
3) For the resulting system, get the corsair 850w PSU (it is enough), whether the TX model or the modular HX one, it doesn't matter.

sparkle psus suck (and are made by fsp so they double suck)

Really? I've read good things about the Sparkle 1000 & 1250 watt PSU both online and on Newegg. In fact, I was seriously considering the one suggested. What is so bad about them?

The Corsair 850 looks good too...

cheap quality i had a 300w sparkle blow up in my face (running a celeron 1.1, 320mb ram, ati radeon 7000 64mb pci) JUNK!

And yet both myself and my friend have been building computers with 350W sparkle PSUs and had no problems at all. Their low end ones are nice and quiet too.

meh.

FSP PSUs aren't bad either, they may not be the best out there, but they are not bat at all. In fact FSP is the OEM for so many brands.