512RAM is a tad on the low side nowadays, so you’ll probably want to go with 1024 DDR2. Keep in mind that ram has a clock speed too, so so if you can afford it getting a stick that runs at 800mhz would be great.
60GB is also pretty low, considering how cheap HDDs are nowadays. You can get a 500GB drive for ~$150, and considering how most games (not to mention media files) are of humongous sizes you’d deplete a 60GB HDD ridicously fast.
About the video card, you’ll probably do more than okay with a DX10-compatible mid-range card such as the nVidia 8600. I don’t know much about computer gaming, though, so mayhaps someone should correct me on this one. =S. WoW’d definitely run flawlessly in such a card, though.
Now, about the stuff you actually /asked/ for >_>.
About whether to go with Intel and AMD, I asked someone on IRC and was told (literally), that “intel be rolling out some fat new fab plants that are spanking amd atm”. Now, I have no idea what it means but apparently AMD is responding around the first quarter of 2008. Either way, I guess that means that the better choice is intel, but I have absolutly no idea about that. ._.
Most procs nowadays are dual core, 64bit and ridicously fast. While not many apps are able to make use of the procs’ dual nature, and very few people go through the hassle of running a 64bit OS (except those crazy vista dudes and some extreme penguinistas) since most of the advantages of doing so are quite limited for the average user in comparison to the disadvantages. Either way, such procs can run in a 32bit environment just fine, so don’t be afraid to get one of them.
About clock speeds they’re all insanely fast now so I really don’t know what’s good or bad anymore. I have a 5000+ proc and it compiles things pretty quickly, but I guess something slower would be okay for someone who doesn’t need to do many processor-heavy tasks.
Another things you should look into are a motherboard (duh) that supports all the other things you’re planning to buy. If you’re building a new machine from scratch that should be easy, but if you’re keeping some of your old stuff finding a mobo that supports it will be a pain. Trust me on this one, I was unlucky enough to buy a socket 939 proc a few years ago. >_>
Also, if you’re going to get a video card, make sure that your mobo doesn’t have integrated video. It’ll make things easier to configure and it’ll probably be cheaper.
If you’re planning to get better speakers, then you should also look into getting a soundcard. I’m no audiophile, but I’ve heard people say that integrated audio and budget soundcards kind of rape the sound so much that getting good speakers makes absolutly no difference.
That’s all I can think about. Sadly, I don’t know how to make ramen other than just buy the instant kind, sorry =(