you dont need a system with those specs
i was planning one of the mini-itx mobos (1 ghz cpu), using the onboard video, 512 ram, and a high end sound card
the reason for the soundcard as i plan on having it directly run the amps, with no head unit
i plan on getting a 7" lilliput touchscreen, a 200gb hard drive, and a 150W car powersupply