If I was going with a local build, I'd just build my own. Sadly, they tend to be more expensive around here. Even worse, the small shops are the ones most likely to collapse in this economy. I know a shpo that makes some good computers, but they've already been talking about closing stores, and they are one of the more stable operations around the Pacific NW.
I'd sweat this a lot more if it were the old days, when a decent machine ran $2500-3000. However, it's a $600 machine you're talking about, and if you watch ads, you should be able to get more RAM than you're likely to need, a bigger hard drive than you'll need, probably two optical drives, a bunch of USB ports and a decent-sized LCD monitor. Astounding compared to the old days (I paid $400 for a 20 MB hard drive in 1987...20 years later, an 8 GB USB drive cost me 1/10th of that).
By a mainstream model, back up your data, and don't sweat it. I'd be pickier if it were a laptop, but I don't think any of the brand names are miles ahead of the others these days.
