Refer to the thread "How to Ask for New Build Advice." We need a budget, usage, and much more info...
HDD: All kinds of wrong. Unless you have absolutely no need for speed and/or space, I wouldn't get that HDD. Go with a 500 GB Samsung Spinpoint F3 for $20 more. This is probably the fastest drive available.
PSU: You do not need a 950W PSU. And you shouldn't get a Coolmax. At most, get a 750W Corsair, OCZ or Antec Earthwatts. These will be quality and provide you with more than enough power for Crossfire later. And yes, that is CROSSFIRE, leading me to...
GPU: Do NOT buy a nVidia GPU right now. ATI is currently destroying them with their new HD 5xxx series. These support DirectX 11, and are faster, quieter, cooler and more energy efficient than anything nVidia has out. Go with a 5770 for an extra $30.
Sound Card: Completely unnecessary. Waste of money unless you're an audiophile...
CPU: Good choice, unless you're gaming (which I assume you are). The best CPU for gaming is currently the i5-750 for $200 ($150 if you're near a Mcrocenter). This will also make the rest of the build cheaper as well. For here down, I'm assuming you're switching to the i5...
Mobo: Gigabyte GA-P55A-UD4P. This board is not cheap (about $180 on Newegg), but supports USB 3.0 and SATA 6 GB/s. Thus, it will be good for a while. It has 2 PCIe slots at 8x/8x, which doesn't sound perfect, but there's actually very little (noticeable) difference between 8x/8x and 16x/16x
RAM: G.Skill Eco 2x2 GB DDR3 1333 mhz CAS Latency 7 sticks. These are good sticks, fairly cheap and low voltage.
APPROXIMATE PURCHASE DATE: In a couple of months, probably slowly buying parts over time.
BUDGET RANGE: Under 1500USD (Not Strict)
SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Development, Home Server, Video Editing, Media Center, Gaming
PARTS NOT REQUIRED: keyboard, mouse, monitor, speakers, OS
PREFERRED WEBSITE(S) FOR PARTS: TigerDirect or Newegg
COUNTRY OF ORIGIN: USA
GPU: nVidia (I have a huge problem with ATI issues and Linux)
HDD: I am planning on doing some sort of RAID setup (probably 5). So I need more than one disk for mirroring or parity (whichever I choose later). What is the best option for speed vs price?
SLI OR CROSSFIRE: Yes
MONITOR RESOLUTION: (1024x768, 1280x1024, 1440x900, 1600x1200, 1680x1050, 1920x1080, 1920x1200) Not of a huge concern but around 1600x1200 would be fine.
IMO, yes. Have you seen anything on the issues with ATI and Linux with their new cards?
As far as the RAID, if you're doing it later, why not get an excellent drive now, and pick up another once you decide?
Strike that. Didn't see the few months timeframe.
If it's a ways off, wait until 2-3 weeks before, and then ask again. A lot is about to change... The new Intel i3 options, new nVidia DirectX 11 cards, whatever SSDs are going to do, more 500 GB platter HDD options... The next couple of months will be very interesting
Instead of a 9800 get a GTS 250. Its the same performance specs but newer mfg method and takes less power. If you were running windows I would not go with an Nvidia card as the ATI cards now have DX11 and have generally stronger price/performance than nvidia.
Right now the best price/performance drive is the Samsung F3 500GB. (or 1TB). It is a new HDD with 500GB platters which makes it much faster than older 7200 RPM drives and even the 10K RPM velociraptors.