My first system build (Gaming, file server, HDCP)

I am building a PC for my family room for the purpose of gaming (on my 60" HDTV and a computer monitor), file server (for media that can be accessed from my laptop and other desktop), and as an HDCP (for running audio and video media files, Blue Ray movies, and possibly watching TV through a tuner card on my big screen). I would like it to be fairly quiet without sacrificing much performance. I also want the best "bang for the buck" in the mid to high end components. Here are the components that I already have and what I intend to buy. Any comments or advise would be greatly appreciated as this is my first build.

Already have:
Sony 60" SXRD 1080P TV (HDMI inputs)
Onkyo SR800 7.1 audio (optical and 7.1 analog inputs)
17" VGA CRT monitor (might have to use this for my monitor when I am not using the big screen until I can afford a nice 22" )
Antec P182 case ($110 -$60 mail-in @Newegg)
Corsair 750W power supply ($155 -$35 mail-in @Zipzoomfly)
2 - 500GB 7k500 Hitachi HDD (for RAID 5) ($100 each @Newegg)

Want to buy soon:
750GB 7k1000 Hitachi HDD for games & backups ($170 - $20 mail-in @Newegg)
SAPPHIRE 100225L Radeon HD 3870 ($190 - $10 mail-in @Newegg)
Intel Core 2 Quad Q6600 (unless I can hold out for the 9450) ($255 @Newegg)
ASUS P5K3 DELUXE ($195 @Newegg)
Patriot Extreme Performance 4GB(2 x 2GB) DDR2 800 ($94 - $22 @Newegg)

Want to buy in the future (in the order that I intend to buy them):
2 - 500GB 7k500 Hitachi HDD (for RAID 5) ($100 each @Newegg)
Acer AL2216Wbd Black 22" 5ms Widescreen LCD ($230 @Newegg)
Patriot Extreme Performance 4GB(2 x 2GB) DDR2 800 ($94 - $22 mail-in @Newegg)
CPU cooler (not sure what yet)
SAPPHIRE 100225L Radeon HD 3870 ($190 - $10 mail-in @Newegg)
150GB WD Raptor HDD for OS & games ($170 @Newegg)


So I have been doing quite a bit of research and this is what I came up with. I am kind of waiting for the Intel 9450 quad core to see if that outperforms the Q6600 for the money, but I have read that the Q6600 will overclock easier. Newegg has open box motherboards, but that seems risky. Decided to go with ATI3870 over Nvidia8800GT since most motherboards that I want support Crossfire and not SLI. I also need an OS. I have a copy of WinXP 32bit, but will probably need 64bit since I want to run 8GB RAM. Let me know what you guys think.

^^^ What he said.

http://www.asus.com/products.aspx? [...] 3=534&l4=0

I suggest this P5K-E which uses the same PCB (board) as deluxe:

http://www.asus.com.tw/products.as [...] odelmenu=2

Or if you can afford it, the P5E vanilla:

http://www.asus.com.tw/products.as [...] odelmenu=2

DDR2 vs DDR3 - most boards are one or the other. They're not compatible.
There are some boards out there that allow either DDR2 or DDR3 -but not at the same time- through extra banks of RAM slots. Sort of an attempt @ future-proofing. DDR2 now-DDR3 later w/the same MB. Gigabyte GA EP35C DS3R
General consenus is that by the time DDR3 makes sense you'll want an improved motherboard anyway.
DDR2 is the best value hands down. And the performance difference between the two isnt that great.
A light CPU overclock with improve performance more than using DDR3.

X38 and P35 have about equal "overclockability". Unless you're going for extreme overclocking performance you can concentrate on the features you want your motherboard to have.

For most of that a 3.0Ghz dual core will outpeform a 2.4Ghz quad - all else being equal.
Use the THG CPU charts to run through something like 35 benchmarks to see where the performance advantages are.
You'll also notice benchmark results for 3.0Ghz quad cores. Will let you approxmiate the peformance of an OC'd Q6600

IMO - $ vs $ - the AMD actually shows up favorably. But when you consider the ability to OC'd the C2D/C2Q family any one even considering overclocking now or in the near future should probably chose C2D/C2Q. The extra performance boost available for OC'ing tips the choice away from AMD.