Going to get 2# airflow build.

I would definitely go with that one too.

It's up to you...but I personally would test both to see which yields better results. Since it's just the orientation of the fans on the H80 that we are talking about changing, that's not hard to do at all. Run it for a week with them in push/pull as exhaust, take note of the temps and the dust, then clean the case, switch the fans to intake and run it for a week again taking note of the temps and dust.

In my mind it can only be an improvement of my own case since it is a larger full tower vs a mid tower, and larger exhaust fans with more cfm exhausting the air out of the top. Also, since you are only using 1 GTX 580 and not 2, you can put the card in the second lower PCI-E lane, it will still run at x16 speed, and increase the distance from the exhaust of GPU and the rear intake, though I doubt that would even be necessary in a full tower case.

Won't hurt to try them bot, and could be worth it...

Few things I found out, the H80 install guide actually suggests that you use the fan as an intake, as it cools the radiator better. You're not using a reference GTX 580, so the heat exhausting out of the back of the case is a non issue, almost all of the heat is dumped back in the case, not the rear. There is no tower CPU cooler, so your case setup will actually benefit from that setup. I searched around and made a thread on another forum about it, and the feedback is almost all the same, rear as intake with the H80.

Any way, at least give it a shot