So, here's what I want. I honestly don't know about many specifics, so I'm very open to suggestions. I'm going to send this post to a couple of local computer sellers, with an offer to just pay a flat consultation fee for the conversation, so that the person makes a fair profit even if I end up buying from a national name brand instead of from them.
The biggest thing here is audio and video. (Presumably, I'll be creating even more as I develop AboutTh.is .) The machine has to be powerful enough to let me make good videos at a comfortable pace, so a better webcam and a better video card. I want to take particular care with the sound card, so as to (finally) eliminate the faint 60 Hz hum that currently creeps into my audios, (and then intensifies with further processing). So, electronically shield both the mic wire and the card? Would a USB mic take care of the electronic interference problem, by digitizing the sound before it travels over the wire? I may even get two microphones, one on a headset, (or a lav mic, maybe?), and another, more professional one, mounted with a pop filter, like you see at radio/recording studios. Not sure yet; I do want the option to be able to get a second mic later.
I see absolutely no reason to install anything more recent than Windows XP. (Frankly, I was very happy with rock-solid NT, but I suspect that's no longer supported.) I do not need Microsoft Office, or frankly anything else installed beyond a browser. I definitely do not want any pre-installed free/starter programs! (I still can't get rid of the Acrobat and Dreamweaver programs that came with this machine because the uninstallers can't seem to get past the fact that I don't have any printer drivers installed.) I want the absolute minimum possible number of tasks running in the background. (e.g., My XP Task Manager usually shows only 15 processes using under 93 meg of memory, compared to my day-job machine that's bloated with corporate-mandated nonsense that often hovers around 1.4 gig.)
As for raw power, I suspect that I'm looking at "gaming" computers, which is fine. How many CPU's? Dual core? Quad core? Memory and disk should both be large and fast, obviously, though I have no idea as far as numbers. And of course I want a very effective cooling system to manage all of this power, so a desktop model is perfectly fine. If it was quiet, too, that'd be great, although I'm not sure that's possible with strong fans.
So, again, I'm looking for input and help. Thanks!