Best Ubuntu machine for the money?

[Jim Carroll]

Hello Vermont Ubuntu (-ers?)

I've run Ubuntu for years on two laptops, and It's my favorite
development machine.  Even though I have a Mac to my left, and a
Windows XP machine to my right, which are both much more powerful than
my 700Mhz P3 Ubuntu system, I find myself gravitating toward the
middle every day.

So it's time for me to put together the machine that I'll use for
software development and 3D visualization programming for the next
decade.  My current choice is a Shuttle P2 machine, but they're out of
stock right now.

  http://us.shuttle.com/ConfigurePackage.aspx?package=XBP2-3700-W

The Ubuntu-powered Dells are not quite as fancy or powerful as I'd
like, and they're showing errors on their website when I try to
customize a XPS 410N.

So, my question is:  If I'm about to spend about $3500 on a serious
Ubuntu machine, and don't feel confdent that I can choose the
components by myself, what's the best box out there?

I do want an Intel CoreDuo (or similar) for the low power / high
performance tradeoff, and I use the Intel Performance Primitives
library, so no AMD... 24" well-reviewed flat panel, 4GB memory, SATA
3Gbps w/ hardware RAID... all the good stuff.

Thanks,
-Jim