Laptop/notebook for digital music production

In the market for a laptop. It's got to handle music apps well (Ableton Live 4/5, SX3, Reaktor 4/5). It's got to make writing music on the train possible. It has to be satisfying in a geeky kind of sense. Ideally it should not suffer from the earth hum problems that a lot of laptops do suffer from.

Things I already know..

Fastest RPM on the hard drive is best (go for 7200RPM).
Need at least 1GB of RAM (fastest as can afford).
On new P4-M systems (Centrino Sonoma) dual channel won't affect things much, since the CPU gets a sufficient data rate using single channel (~4GB/s). This means I can get a single RAM chip to make upgrading cheaper later.
CPU can also be upgraded later (warranty will be void, but who cares...). This means the CPU speed can be skimped on a bit now to save $$$.

Things to consider..

P4, P4-M (HT?), or Athlon64M

From Interesting link #2: looks like Athlon 64 3400 (2.2GHz) is significantly better than the P-M 740 (1.73GHz) which are roughly equal in price for the systems i'm looking at. But what about RAM, FSB, and Video performance?

64 bit

- Can run XP64
- M-Audio is getting into 64 bit drivers

Graphics

ATI X300 > X600 > 9700 Pro

Model systems

http://www.digitalaudiowave.com/index.asp?PageAction=VIEWCATS&Category=3
http://www.awave.com.au/product_info.php?cPath=125_144&products_id=1999

Interesting...
1. http://www.tadpolecomputer.com/html/products/mobile/
2. http://www.systemshootouts.org/processors.html
3. http://www.clevo.com.tw/products/default.asp - these guys seem to supply most of the rebadged systems (incl. Alienware, Asus)
4. http://www.notebookforums.com/index.php [excellent user-sourced laptop info]

The Contenders

- Apple Powerbook 15" 1.5GHz
Verdict: too expensive for feature set.

- ASUS A4030K 15.4" AMD64 3400+
Verdict: Good notebook, fairly limited battery life. Cool because it'll run Win64. There are similar 17" versions though.

- DigitalStar Z71P (built-for-Asus) P-M 1.86GHz, 1GB, 15.4"W
Verdict: This is the one i'd go for. 5.5 hrs battery. Will run pretty much anything. Has the latest Intel mobile chipset, including PCI-E. The only downpoint is that it has crappy AC97 sound, not the Intel HD chip that some Asus models have.

Final Words

My advice is find a shop which will customise a barebones laptop. I think the Clevo or Asus based ones are pretty good. Also Mitac rates a mention. That way you get things like 7200RPM hard drives, and the fastest RAM, which the pre-spec'd ones rarely have. In the case of the 7200 rpm drive this might cost you an extra $80 but will greatly improve your experience.

Be careful with screen quality. Run some dead pixel diagnostics as soon as you get the machine. Read plenty of reviews. notebookforum is good for this. That's it!