Review Requested (first time/$1000/gaming)

I've been planning on buying a new computer for a while now, and would have bought one a few weeks ago, but it wasn't the really the ideal time financially. I now plan on purchasing the parts some time between the end of this month and mid October.

I'm trying to keep it at a $1000 US budget, and have spent a lot of time picking out the following parts. The primary use for this computer will be gaming, and it would be my first time building one.

Motherboard: Asus P5QL Pro P43 -$94.99 http://www.newegg.com/Product/Prod [...] 6813131329

CPU: C2D E8400 3.0GHz -$169.99 http://www.newegg.com/Product/Prod [...] 6819115037

Memory: 2x2GB OCZ Reaper DDR2 800 (4-4-4-15 2.1v) -$105.99 -$20 MIR http://www.newegg.com/Product/Prod [...] 6820227267

GPU: VisionTek 4870 -$260.00 http://www.newegg.com/Product/Prod [...] 6814129113

Hard Drive: WD Caviar 640GB 16mb cache SATA -$84.99 http://www.newegg.com/Product/Prod [...] 6822136218

DVD Burner: 22x Samsung SATA -$25.99 http://www.newegg.com/Product/Prod [...] 6827151173

Case: Antec Three Hundred -$69.95 http://www.newegg.com/Product/Prod [...] 6811129042

CPU Cooler: AC Freezer 7 Pro -$24.99 http://www.newegg.com/Product/Prod [...] 6835186134

Case Fans: Two Evercool 120mm's -$4.79 each http://www.newegg.com/Product/Prod [...] 6835119045

PSU: Corsair 550w (+12v@41a, +5v@20a, +3.3v@30a, 80+ cert.) -$97.99 -$20 MIR http://www.newegg.com/Product/Prod [...] 6817139004

OS: Vista Home Preimium 64bit -$99.99 http://www.newegg.com/Product/Prod [...] 6832116488
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$1044.45 and $40 in MIR. Right on budget, before shipping and taxes.

And, I think I'd rather pick up some thermal paste at a Bestbuy or something, I don't wanna pay shipping on it.

Whew! Alright, now, I plan on using this for gaming for the next two to possibly three years, and then building an entirely new one from scratch.
-I picked a P43 motherboard because it has all the features I need, and I've no intentions of crossfiring on this system.
-I'd like to overclock the E8400 to 3.6GHz, because that seems to be the magic number everyone suggests for it, and I've never overclocked before.
-Memory, there are just so many good deals on DDR2-800, I just picked one that seemed like it was quick, but I guess 2.1v is sorta high? I'm not sure here.
-ATI's 4870 seems to be the best choice in my price range, but I just noticed the GTX 260's price dropped significantly recently, so, not completely sure here.
-The case, fans, and CPU cooler just seemed like fine choices. I like the case, which has a 120mm back fan and a 140mm top fan, and will fit the two extra 120mm's as intake fans in the front.
-The DVD burner and hard drive seem like good deals, and are both SATA.
-The PSU was a tough one, but it looks like the Corsair 550w should cover my system's needs, and has all the right connectors, I think. Though, I'm very, VERY open to any suggestions here, or anywhere really.
-Vista 64bit is, well, Vista 64bit.

One thing I don't know much about, in particular, is the relationship between my memory and my CPU, and what it means when overclocking. I'd appreciate being directed to a good, easy to understand guide, or just have it explained here if possible.

I'd just like these parts looked over by people that might know a bit more about building than myself. Like I said, this is my first time building a computer, and I'd like to get it right, since I'm spending a lot more than I'd usually spend on an entertainment/luxury item.

Thanks.

edit: reorganized

Look for a motherboard with a sticker on it that says "Certified for Windows Vista" if you're even thinking about running Vista 64. Look at the Gigabytes they almost all have it. Other stuff matters little unless you can squeeze bigger PSU and 4870 x2 in somehow

Well balanced, well thought out system. I could nitpick a few things, P45, E8500, Mushkin RAM, but they would be nitpicks. Good luck on a solid build.

Oh, you're right, I didn't realize that. Only $1.82 shipping on the Arctic Silver 5. Thank you.
I added the fans because, well, it just feels like I'm wasting the case. I suppose ordering without and picking them up locally if I need them couldn't really hurt. Thank you.
I would like an E8500 and a P45, but dropping those down were part of the reason I was able to add 4870 instead of a 4850, while staying down on price.