I have one that can do that. It has a 15.6-in TFT display, Firewire, USB, DVD, LS-120 "A" drive,and a 700 P3 Mobile CPU. I would avoid AMD in laptops . . . they do not yet have a good low power, low heat Athlon. One is coming soon, but it ain't here yet. The enemy of laptops is heat. P3 Mobiles run cooler than AMDs.
For desktop use you will probably want to connect a regular keyboard. Typing on a laptop constantly sucks. The touchpad is a pain in that regard because hand and wrist movements on it give one fits while typing. So, a regular PS/2 or USB mouse (optical) is also in order for desktop use.
I use mine (when home) as a CD/RW burning station with a QueFire! 16X Firewire external burner. It works beautifully with no coasters.
As for brand, Dell is good, H-P is good, IBM is good, and so are Sony and Gateway. Those are the only ones I have experience with, and others are undoubtedly good as well.
Dell and IBM are my favorites because you can disable the touchpad and use the pointing stick if you are mouseless.