Seems pretty balanced and low cost, which I presume are your goals. About the power supply, you should have your total power draw (which you should have added up, including motherboard and memory) under 280 watts -- the 20% margin is a good practice. Also, consider what kind of graphics card you could upgrade to in the future. If you knew that in time you'd likely want a beastly powerful graphic upgrade, you'd have to have more than 350W then. On the other hand if you don't expect such ambitions, there will eventually be 8000 series cards on the low end in a year that will draw relatively low power compared to the 8800GS, though I won't hazard a guess at exactly how low. One way to guesstimate would be to compare the 7800 or 7900 (take an average) to the 7200 and 7300s (again an average), and multiply that ratio vs the current power draw of a 8800GS as a kind of educated guess.
I was mostly trying for balanced and low cost. If I ought to have a 20% margin, the power supply does look pretty borderline - I get 294 W using the eXtreme Power Supply Calculator v2.0, so maybe I ought to look at switching to a 400-450W power supply to be safe and allow for expansion in the future to a nicer video card and more RAM. I know it's not the most exciting system ever to be built, but I really appreciate your taking the time to look at it.
A faster hard drive would definately be worth $15. Is it still relatively quiet? Most of the reviewers at Newegg seem to say yes, although I saw several who claimed they could hear if across the room (something I'm trying to avoid).
there are a *lot* of 7200.10 drives, and you should expect them to be a little different from each other in that regard! Same for other brands. See they aren't all manufactuered in one plant, even for the same family of drives! So you read thru reviews or search thru for "noise" for several canidate drives (distinct model number) until you are satisfied it's a good choice. Finally, because the drives are made to be affordable there is indeed a portion, for each manufactuerer, that are noisy or have a problem, so there's always a possibility of having to do a return ("RMA"). I am picky, and have returned 2 drives out of 12 or so I've bought, but I think 5-10% is a good representation.
It will cost about $55 more for this combo than for the AMD I had in my initial post. Will I get $55+ worth of increased performance? I may do some mild overclocking, but won't be pushing the limits since I want a stable system.
Thanks for the help. Right now I have it around $620, including Windows and a DVD writer. I could go up another $100 or so. I was given a video card, so I don't need that now (until directx10 cards are reasonable).
Some will like my choice of PSUs, but I have one, and it works well. If this is too much, I have an AMD version up my sleeve, but for the price difference, I'd stick with the Intel. It's faster out of the box, and will OC like a dream if you decide to do so.