If 10lbs is ok the Toshiba P25-s520 is a good choice.
Any Hyper Threading P4, 3ghz or higher with a 800mhz bus should work great.
Make sure that the video processor has it’s own memory and does not use “Shared System Memory”.
Also, several USB2 ports are a must. Firewire is good, but if you want to preview the results on a regular tv it will be plugged into the camera.
Other than that, pick the one that stands out to you.
Scott