Let us know how it ends up
It ended up pretty well. I'll summarize my thoughts on some of the components and the overall system below, maybe it helps others who are upgrading or building a new gaming system.
Case: The NZXT phantom is not cheap, but it looks like it was plucked straight from a spaceship in Star Wars, and the geek in me jumps around gleefully when looking at it:
http://www.nzxt.com/new/products/crafted_series/phantom
Overall I am happy with it: It has tons of space, is finished with high quality, and allows for good cable management. Given the price I still have some niggles though: I missed a cable channel or "cable gap" for the SATA and power cables going to the HDD bays - there is a metal ridge in the back going from top to bottom that leaves relatively little space to the side panel when that is mounted, especially when you have damping installed. The cables have to go over this ridge, or inelegantly through the crack between the mainboard support plate and the drive bays. Other niggles: The screws (e.g. the spacers for the MB) sometimes required considerable force to go in, either the threads are cut poorly, or paint got in there. No problem with a phillips screwdriver, though. Secondly the fan control sliders appear a bit flimsy, and one was initially stuck in a halfway position - here they could up the quality a bit. finally I am not convinced by the slide in drive trays. They use rubber washers with a metal pin instead of screws. They were a bit difficult to get in place, and for the SSD, which has to be screwed onto the tray, the back pin can't be inserted anymore. The pins fell out several times. In the end everything worked out OK, though. finally the case has no 3.5'' drive bay, so I couldn't put in the SD card reader I had ordered. So I'd fully recommend this case if you like the look, otherwise there may be better choices.
MoBo: Asus P8Z77-V. As Moriendor said it has everything I need and quite a few features I don't need. Well, almost everything I need, I would have needed a second internal USB 3 port if I had been able to install the SD card reader in the first place. The one it has is taken up by the case front panel connector. Secondly it only has two 6GB intel SATA ports, while the other two 6GB Sata have Asmedia controllers. Once these are connected they slow the boot process a little. Not sure what the sense of this setup is, to be honest.
Cooler: I got the Alpenföhn Himalaya, a slim tower cooler.
http://www.alpenfoehn.de/index.php?...ew=article&id=178:himalaya&catid=53&Itemid=44
It's huge but looks really good, imho. Performance is great, playing Skyrim, the CPU hovers just above 40°C. The fan is not recognized by the mainboard but it doesn't matter as the cooling is great and it is absolutely silent at standard speed, so regulation is not necessary. One thing I hated though: the manual is pretty useless. Only drawings, but printed so small that they would make a chines rice grain drawing artist proud. Of course one would eventually figure things out, but without a great video i found online it would have meant a lot of trial and error, and that's something I hate, especially with this most critical aspect of the whole building process. So in summary: great engineering, really poor manual.
GPU: I went for the Gainward Phantom (560) that Moriendor recommended and am very happy - its practiacally unaudible in 2D/idle, and never gets loud. Performance as you would expect for a card of this type - and it stays quite cool: Skyrim got it to just over 60°C.
Samsung 830 SSD: Having an SSD is great, love how quickly the OC loads. The Samsung comes with a full version of Norton Ghost, which is a nice touch for data migration and later backup needs.
PSU: Coolermaster Silent Pro 700M: Indeed very silent, and worked very well. the main ATX power cables and SATA power cables could have been a tad longer for this case, but it all worked out.
Monitor: I stuck with the BenQ G2450HM (16:9) forgoing a 16:10 mostly for budget reasons. It works well enough, big improvement over my old monitors. But it seems the HDMI port is out of order - I think I can't be bothered to send it back though, I just have it on DVI now. The other thing that gave me pause was that it was packaged only with a D-sub (VGA) cable - who is using these anymore these days???
Silence: Wow, what a difference to my old system! Thanks I suppose to the large case and the excellent cable management, I can run the case fans at the lowest speed and still get excellent cooling (see above, the chipset remained at about 32°C during gaming.), inspite of having put quite a bit of dampening in the case (not covering main air inflows, though). In this state I can hardly hear the system sitting at my desk, and don't hear it at all with my headphones on. Yay! (I should caution that sound enthusiasts (or people with better ears) would maybe evaluate this differently, but for me it is more than silent enough, completely surprised me how well it works, actually). Nothing overclocked currently, but I would think it may be possible to do some and still keep the system quiet.
Overall I am very happy with what I got. A huge upgrade from my 7 year old previous computer.