What size battery should i buy?

so I'm going to buy a yellow top to feed my 3000w rms amp and my 2 1600w subs. i was jus curious on what size battery i should order? i already have a optima red top as my main battery in my 1996 chevy lumina and i found a 870 Amp, 55 AH Deep Cycle Optima Car Battery (yellow top). would this be big enough or should i go bigger?