The laundry bags drag in the water and slow you down much more than livewells. Instead of using a 12 volt battery and bilgepump or aerator, go to the hardware store and buy a couple kerosene pumps. They work pretty well and run on D batteries.
By the way, try using a plastic storage container instead of a cooler as your livewell. You'll have to drill drainage holes in it so the water doesn't over flow.

Good luck
Chris