For the most part, I think everyone is covering most of the bases, but if you're asking which company I'd personally buy from in this, I'm gonna say to contact an HP sales rep. I have an HP Pavilion, which is the VERY first computer I EVER bought, and that was in 2000.

The machine is currently my FTP Server. Because it STILL works. The ONLY problem I've ever had with that machine, is that a few years ago, the video card in it started to go. I first tried different monitors, and it was the same, and figured out that it needs a new video card. It basically makes a GUI look ugly is all.

I started using it as my FTP server, and it's on 24/7, and without a GUI it looks just fine. And most of the time I use it through SSH anyway, so, really, it's not much of an issue. But the fact remains that the 43 GB (Yes, 43) Hard Drive it came with, which I'm not kidding; Has been Formatted and had full OS re-installs, Partitions all over the place, and ALL that, is STILL working.

10 years and only the video card has given me even a small issue. The rest of the hardware still works great.

If you're going to be buying in bulk like you seem to be going for, see if you can work out a deal. You might be able to get them to sell the machines to you for a cheaper price.

Anyway, just wanted to pop in and say that the HP machine I have is still kicking after a decade of VERY heavy use and even Heavier Abuse lol.