Where did you get your Thermaltake from? I want one as soon as poss, but it seems to be out of stock everywhere.
As for the fans, I'm not much of an expert
I've read lots of reviews, but can't seem to come up with any good conclusions. I can say though, that I've tried the Noctua 1200rpm and the Sharkoon 1000s. The Sharkoons are fantastic because they are just so quiet, but they dont move much air. The Noctuas moved more air, but where significantly more noisy than the Sharkoons, even though they had a lower DB rating in their tech spec.
As for the Scythes, I wouldn't know which is best, although they aren't hard to research on google, because they are so popular. But my bet would be that going with the 1600rpm would be best, because you can lower it with your fan controller. Its easy to slow down a fast fan, but you can't speed up a slower one.
So as long as you get a good one, it should slow down and be nice and quiet, and yet still provide good air flow. The Scythes are really popular so shouldn't let you down, although Clunk recommends "Yate loons for £1.50 each from jabtech and a fan controller any day of the week"
Sounds like a good bet to me.