UPDATE
The project is nearing completion. I have chosen the following system now (and its built too!)
Celeron 400
256 SDRAM
30 Gig 7200 RPM Maxtor
20 Gig 5400 RPM Maxtor
ATI All in Wonder 128 PCI
IRMAN
5.6" LCD on Swivel mount from DigitalWW on passenger dash
Fellowes Touchpad (on order) for backup control
LineX USB FM Modulator / Sound Card (Mind Factory giving me run around, ordered a month ago.........)
Power:
Had to ditch the MPBS1 due to power issues

In the meantime decided to go with a 300W inverter to get the job done (yes, it, my powersupply and motherboard are all grounded!)
I had an issue getting a signal to my lcd, here is what happened and how i fixed it
Problem : The LCD i had is a passive device. My TV-OUT would not recognize it to save the world. I tried the 75 ohm cable, i tried a 75 ohm resistor, but to no avail.
Solution:
I rationalized that it detected my television / vcr fine because its an "active device." So, what could inexpensively and simply emulate one? A signal amplifier of course! But radio shack doesn't have a simple one, i found a cheap video 4-way video distributer and hooked it up. I had a POST! Problem solved!
Future Plans
DVD-ROM
Sharp 10.6" LCD i can get from work for $120

(retail : $699)