Quote - IMO no products "need" to be retail except the motherboard, as you noted, for included connectors and cables.  It only really affects price, you still have the manufacturer's warranty.  The manuals for various things are all junk that will sit in a bottom drawer somewhere, if you don't actually throw them away (I do).

The difference in price between OEM and retail can be quite large, although in your case it looks like the various bits are within $20 of each other.

According to Louguet here there is an almost insignificant difference (1-2%) in render speeds when using different speeds of memory.  You can save quite a bit of money by going with 667MHz memory:
http://www.newegg.com/Product/Product.asp?Item=N82E16820231112
800MHz, $399

http://www.newegg.com/Product/Product.asp?Item=N82E16820231110
667MHz, $369

I bought the 2x2GB 800MHz G.Skill memory and it works fine with my ASUS P5WDH Deluxe motherboard, so I'd expect it would work fine in yours, although in my case the motherboard won't actually run it at 800MHz, it slows it down to 533MHz (meaning you're likely just as well off buying the slower mem and saving 30 bucks).

VERY interesting!  I just checked the specs on the motherboard you mention and it says the following:

ASUS P5W DH DELUXE/WIFI-AP LGA 775 Intel 975X ATX Intel Motherboard
AGP Slots: None
CPU Type: Quad-core / Core 2 Extreme / Core 2 Duo / Pentium
Dual Channel Supported: Yes
FSB: 1066/800MHz
Maximum Memory Supported: 8GB
Memory Standard: DDR2 800
Number of Memory Slots: 4×240pin

Clearly I have much still to learn since I would have thought this setup would support DDR2 800 RAM running at full tilt.  But if not, then I can indeed save $30... twice! 

And thanks again on the OEM vs retail insight.  I'm thinking I might aim for OEM on the HDDs but stick with retail on the motherboard, as you suggest.  And I've seen many complaints on newegg about hardcopy manuals, and that you're better off just downloading the electronic version from the manufacturer's site anyway for better readability, so no need to go retail on most things it seems.

thanks again...