I can get up to 12% IIRC at Dell, and I think a little more at HP. I just don't know if I want a pre-built; the components aren't usually worth the amount IMO...
Looks like tiger has some good deals on the core2 quad bundles (socket 775), pick one of them in the mobo flavor that suits you. That should be the best bang for the buck
I vote for AMD I always use them they handle pretty well all be it a bit warm. I'd check with price 1st if an intel 3GHz is cheaper then an AMD equivilant then go Intel, otherwise I say AMD.
MOBO I always go with asus, i have never had many problems other then selling the old systems to freinds and then they abuse the pc and kill it...then I have to repair it, besides asus mobos come with a wifi card built in, or at least teh last 1 I bought, I imagine you could get a decent one.
Video card I was all about NVidia and still am but ATI isn't that bad since its now part of AMD and my asus F7 notebook has an ati in it. Also for a vid card, if you want try and get one with an HDMI plug that supports audio out, always nice to be able to toss up ur desktop screen on a 32"+ flatpanel provided you have one, or at least a tv that supports HDMI.
Memory 3GB is all you need.
HDD WD all the way.
As far as Raid no idea never ran raid setup before.
OS I'm with ya there Vista sucks, and with MS planning on or last i heard planning on stopping updates for XP I Dl'ed W7 beta and I like it. It's got the look of vista and the features but the feel of xp.
Intel is much better than AMD in the multi-core realm.
I've always liked Nvidia over ATI, but the long-run result is that they always go back and forth for whoever has the best card, but Nvidia has always had superior drivers.
Raid 0 is still very good, but rather than stripe a couple 200gb drives its faster (and not very much more) just to buy a single WD Velociraptor 10K RPM 300gb drive.
One must remember striping increases data read/write but does not quicken seek time (actually worsens it).
i7 - newer lower power version - mid range $300 and OC it 50%
Really good silent air cooler
Evga MB - guaranteed for life and good for OC
Evga graphics single card mid range $150-200 - guaranteed for life
Min 6gb more likely 12gb ram - tripple channel - its cheap
Drives a couple of chunky 750/1tb - skip raid - with that much memory you arn't going to disc often