As far as system use, I do some video editing/rendering, but I do not really use this system to play games.
If you actually don't game, spare some hefty bucks over the GPU and pick a Sandy Bridge, rather: it's far better for CPU-based rendering.
It isn't clear to me your dual DVI requirement: do you need just dual DVI, or two digital outputs (as a DVI plus a HDMI)?
I would rather this one
, it's too much quieter than that Seasonic (and it has the right wattage).
I looked at the Nexus 430 before settling on the Seasonic, but I may yet end up going with the Nexus. I'll re-read the review. Thanks.
I'm taking the liberty to not agree with our kind host (MikeC): if you have to threw out of the window a five year warranty and add $17 for a good Scythe fan to have the S12-II substantially quieter, then it's a smarter move to go for a different, maybe more expensive PSU.
In the low-end range, something like an Enermax ECO-80 II, or an Antec TruePower New are far quieter than the S12-II and may be well suited for you, particularly if you go for a less expensive videocard.
About more expensive units (around $100), a Cooler Master Silent Pro (NOT the Golds), or an Enermax Pro82+ may be also well suited (or if you trust MIRs, higher wattage XFXs - Seasonic based - are simply excellent): over that amount, an high end Seasonic X currently is a no brain.
Moreover the S12-II 620W is clearly a waste of efficiency: sticking with a low end Seasonic, a modular M12-II 520W is a better option (same money, higher marginal efficiency, less mess of cables).