Wow thats some serious hardware.
Few things though, first off the 6670 is seriously underpowered for some of the newer games (bf3 and then so all Frostbite 2 games eg Warfighter, the new C&C, other games too eg Arma 2 and thus DayZ). Not sure of the ATI equivalent (Nvidia all the way
) but I've been looking at upgrading too (9800gt is lucky to hit 20fps at any decent resolution, don't even talk about a grenade going off). Best bang for buck would be a 560ti and should be ok for a while but if I were you I'd cut back on some of the rest and go for a 660+.
This is more of a personal choice but for me I got a Razer Blackwidow Ultimate and Razer Mamba and never looked back. The keyboard is amazing (its hard using a non-mechanical keyboard now) and its nice having the ability to go from wireless to wired for charging in the mouse. Also the keyboard has has a few accidents (water only) and was fine after drying out for a day or two. They're worth a bit more though than the ones you were looking at.
Not sure on this, this is just my personal preference. I recently upgraded to a full tower case from a mid and except when you need to move it it is worth it. The extra space is great and seems to keep everything cooler. The Thermaltake Chaser Mk1 is awesome (my case) best part being you can turn of the lighting (and dust filters are great if your in an older house) - thing is it does look a bit more flash and well a tad, gaudy. Not too much more from your pick (here in AUS).
The PSU sounds ok for that gpu (AMD says 400watt min 500watt recommended for the 6670 anything higher gets higher) but if you are going to be running anything more in the future (plus that water cooling cooler) I personally would go for something with a bit more bang (I'm no expert on PSU's but that's my guess). Yeah the 480 would need more as it was a higher tier GPU I think (if the newer gen's use the same number system [550 lowest 580+ higher]).
Yeah sorry for the block of text, most of it is just my personal preferences but well, yeah.