1000w will most definately drain the battery quick, and its very excessive for a cooler. If you want to do straight to aux for an amp try a memphis street reference 50x4. Definitely go with a dry cell battery. you really dont want acid battery near your cooler especially if you plan to still use it as a cooler. This is my best advice tho man. http://www.algator.com/atv-audio.htm <--- thats what the shop i use to work for does for atv audio. about 95% of the time we use memphis power reference or memphis marine speakers.(www.memphiscaraudio.com) and we use head units so you can have cds and ipod hook up. The speakers get loud off of head unit power. 2 sets of 6.5 running off a head unit will do more than what you think it will, and if you can hear it clearly over the sound of a running atv then you should be fine with it for a cooler. The way we power our atv boxes is from the battery on the atv, but since you don't have any type of recharge system you can do this: permanantly hook up a small motorcycle battery charger to the battery and have the wire come through a hole somewhere on the cooler and monitor the voltage of the battery with a voltage meeter, you can pick up the meter and the dry cell battery from stinger. any time it drops below 11v then simply go plug it in or turn it off.