WTF?!?!?!But as for my computer, I'm going to need A LOT of power, I plan on running between a 1200-1400 watt PSU.
My god, man... WHY?!?!?!?!
The butt-kickingest gaming PCs don't need a PSU that potent! What on earth are you planning on doing with an uber-powerful PC in the car? And why do you think you need a 1200w PSU? What hardware do you indend on running?
Hell, a high-end gaming system with a couple of 10,000rpm hard drives, dual high-end video cards running in SLI, two optical drives and the fastes Intel EE CPU made overclocked to its melting point with a freon-based cooling system can use a 1000w PSU.....
Even if you were contemplating a system that potent in your car... Why? What would you be doing with a bad-*** PC in the car? Are you planning on some uber-fast 3D renderings or playing the latest and greates games in the car?
I'm not going to recommend a battery, because I don't know.-What size battery would you recommend for this kind of power consumption, and approx how long to you think the battery life will last (hrs).
I will, however, recommend paring down your PC specs to something less powerful, as any setup that requires a PSU that substantial is severe overkill for the car.