Regarding WD drives: Almost everyone I've spoken to has had poor experiences with either WD and Seagate and positive experiences with the other (though some prefer samsung, etc., but the vast majority is who I'm speaking for here). If you tell one person you're getting a WD they'll pat you on the back, and the next could have a series of complaints against them. The reason I chose the drive I did was the 5-year warranty. I'll be setting up my external via USB and backing up every night until I can set up in a RAID1 configuration for internal backup. Would do this with any HDD, so the 5-year warranty and generally good performance tipped the scales for me.
I've never met anyone with a bad word to say about Corsair. I don't need anything ridiculous so I think $100 for a 650w Corsair power supply is the best $100 I could spend on powering my computer.
I've already ordered 8GB so I can't really use 4, as each stick is 4...I'll look to buy two more sticks when the same RAM is being phased out for cheap as there's no need to put in 16GB for anything at this point...
As for the 6950, it's way way more than I'll ever need and I can overclock the 6850 to (more or less) 6870 specs with no problem. The biggest plus to the 6850 is the single 6-pin power connector which is great if i end up doing Crossfire as it pulls less power. I don't need a monster video card setup so Crossfire is probably unlikely unless Skyrim is incredibly demanding and I need a second GPU to make it look nice.
I did a review of my case, an AZZA Solano 1000R:
(I didn't have the bottom left panel screw full tightened which is why you see the red stripe)
It's a full tower and though it doesn't have a removable motherboard tray, there's a hole for an aftermarket CPU cooler retention plate if that is something I end up considering. Otherwise it fits my needs perfectly.
PSU and other items should start rolling in Monday.
-Ben