All hard drives have a usuable capacity less than the stated capacity so you probably won't improve any there.
The Compaq X1000 (sister to HPZT3000) notebook I have has a free upgrade to a 80gb 4200rpm hard drive from the cost of a 60gb 4200 hard drive if you want to get another 20gb in hard drive size (but you may be better off ordering the 5400rpm 60gb hard drive which is 50% faster in seek time for $25 more than the 60gb 4200).
At any rate the Toshiba M35S456 (see other recent posts on this board) is an outstanding prebuilt notebook (at Circuit City on sale this week and Compusa on sale this week -- closeout pricing on this particular prebuilt model). Compusa has it for $1749 for remaining models and I think Circuit City's price may be $1700 (see other recent posts here on the Cnet notebook forums). This is fully loaded with the Trubrite LCD, multiformat DVD drive (all formats), 512mb PC2700 RAM, 80gb 4200rpm hard drive, etc. It has everything you want, weighs 6.2 pounds (15.4" widescreen). It runs a bit warm around the touchpad area so try it in the store but that is about it and they are going to be gone after this week. Since you want a DVD burner this s a great value for you.
The only thing missing from your list is that the Toshiba M35S456 has 64gb dedicated Nvidia graphics and the HPZT3000/Compaq X1000 series I have has 64mb dedicated ATI 9200 graphics.
Both of these are slower than the ATI 9700 video card. If you really want this you need to look at the Dell 8600 which has the 128mb dedicated video card ATI 9700 (and also 7200rpm hard drive option which is very fast) or the Acer 2000 series (also has 128mb ATI 9700 video option) .. the Dell has a lousy keyboard and its case is too wide and heavy but it has the components you want. The Acer is a good value but it can only be bought as a prebuilt online but check that out as it has what you want.
However, if you are willing to stick with 64mb Dedicated video somewhat slower than the ATI 9700 get the Toshiba M35S456 (where you get the Trubrite -- Dell or Acer does not have this yet) or custom order the HPZT3000/Compaq X1000 (they just got HP Briteview online -- not in stores yet).
See X1000forums.com for all the discounts and best specifications on the HP. Before, the HP didn't have the Briteview or the multiformat DVD burner (only DVV+) but now you can get a multiformat DVD burner in 2 speeds online. Also, you can order 256mb RAM and add your own 512mb PC2700 RAM (example: Kingston notebook RAM PC2700 for $79.99 after rebates this week at Best Buy) for much less.
And, you can get a $100 custom order rebate for any HP or Compaq custom order notebook through 12/1/04.
Grab the Toshiba M35S456 quickly retail if you want that or look at hpshopping for the HP/Compaq if you want that.
Otherwise, get the Acer 2000 series but that will put you over $2000 (Toshiba is $1700 fully loaded with Trubrite and the HPZT3000/Compaq X1000 can come in around the $15000 mark after rebates/discounts especially if you order less RAM upfront).
For the Toshiba, look at www.notebookforums.com (a few Acer posts there as well).
For the HP/Compaq X1000forums.com/hpshopping.com