My dream book would have to be this:
Voodoo M860
Athlon 3700+
2gig RAM
Radeon 9700 (yes, I take recording breaks to play Jedi Academy

)
1680x1050 15.4" widescreen
60gig 7.2k HD
WinXP Pro
A mere $4400. For comparison, the Compaq R3000Z, closely configured:
Athlon 3700+
2gig RAM
MX440 AGP (yuck.....but perfectly fine for audio)
1680x1050 15.4" widescreen
WinXP Pro
80gig 5.4k HD
$3005.00
Both use the nForce3 Go 150 chipset, so they should be good for audio compatibility.
That being said, I am still going strong on my Gateway with 1.3Ghz, and I am probably just going to get a Toshiba 80gig 5.4k HD, w/16MB cache, and maybe another stick of 512MB.
With Audition, freezing tracks works wonders and saves me money. hehehe