I just ordered (today actually!) a Dell Latitude E5500 for a user @ work. It's a pretty nice setup. As for sound, I'm not sure. I've never really had a laptop that compared to a desktop in terms of audio. Here's what's I got for $1400....
15.4 inch screen
Core2Duo T9550, 2.66Ghz (6MB L2 cache! 1066Mhz Front side bus!)
4GB RAM
22 inch widescreen (external monitor)
Docking station
160GB HDD (7200 speed, not the typical 5400rpm laptop ones)
Vista business > "downgrade" to XP + you'll get Win 7 for free when released!
8x DVD/RW
Wireless
9 cell battery
Office 2007 Pro + Acrobat 9.0
3 year next business day warranty
MS Office was $349. 3yr warranty was $219. The monitor was $199 extra. Dock was $129 extra. Upgrade to 9 cell battery (from 6) was $76.
Oh ya, you have to use promo code "H353Z0GPC593DB" which is 33% off laptops priced over $999. The pre-promo total for my laptop was $2400 I think.
Pretty much most all non-netbooks will easily handle the tasks you stated. Hell, you could get a dual-core, 2gb ram, Dell Vostro for $600 if you don't need docking capabilities.
Be sure to check out
http://www.cheapstingybargains.com and
http://www.techbargains.com before you order one though
Things to remember:
1) You pay a premium for 17" displays. The 15" displays are most common, the least costly (obviously).
2) Battery life of a 17" compared to 15"
3) I don't recommend the 5400rpm laptop drives. This is DEFINITELY a bottleneck. Go for the faster 7200rpm, it's worth every penny. Hell, get a solid state if you can!
4) Don't use Vista
