Hot import nights.I am thinking about puting it in the show but here is the problem.The battery has to be disconnected ,So what do i use for the power.I can buy power for my car but,i need to change it to 12volts.I have not been able to get a strait answer.A couple of people have said to use a battery charger with high amps---but will that be enuff for a dvd,ps2,neon,and about 2100 watts of power.Any ideas for this?a INVERTOR that is reverse is what i thought i needed but i cant find one with high amps

An INvertor converts 12VDC to 120VAC. you need what's called a '12V power supply'.

As for how big, add up the sizes of fuses on all the circuts and get a power supply that big.