I purchased this on sale awhile ago for $90
Even at current $109 it is still an excellent vale.http://www.newegg.com/Product/Product.a ... 6817182073
Re: some of your concerns
SLI and Crossfire cert. is just what it says: a formal submission process and granting of a labeling right= certification.
Adds extra cost and time to the PSU, and really doesn't mean anything in particular.
Most new units are 6+2 on the eight pin PCIE = fine for your six pin card.
5 year warranty.
This is the first superflower OEM unit made for Rosewell, the house brand of Newegg.
While Rosewill is not always known for absolute best quality, in this case it is a very solid OEM.http://www.jonnyguru.com/modules.php?na ... 5&reid=266
PS the AMD 6870 is only a 140 watt card max. in Crossfire it will be well less than the 2x of that figure closer to 250 watts than 300. (unless you are folding or or distributed compute.)
Consequently you will never see more than 500 watts from your described rig gaming usage.
THerefore you could easily consider :
KINGWIN Absolute Platinum Series AP-550 550W ATX 12V v2.2, EPS 12V v2.91 and SSI EPS 12V v2.92 SLI Ready CrossFire Ready 80 PLUS PLATINUM Certified Active PFC Power Supplyhttp://www.newegg.com/Product/Product.a ... 6817121094
Had been at $180 but recently reduced to $109 to compete with ANTEC intro. (all be it with the conversion from modular)
With out a doubt one of the best quality units on the market today.
PSS Regulars might notice some redundancy in my recommendations
Been following the market for some years due to interest in folding and efficiency.
Unless you need $40 cheap, these just happen to be two great values in the market now and they cover a pretty wide range of requirements.
I don't own stock in either company.