Re: Add a livewell??
"I too am interested about this...how do you recirculate the water in a stand alone cooler livewell? Do you get a bilge pump and toss it over when you stop to flush new water in? Whats the best way to go about this?"
The ones made for a cooler usually just draw water off the bottom and stream it in the top. Frabil and others make 12V bubble airators. While, I currently do not take a live-well with me, do use allot of minnows in the fall. Bubble airator works very well. I might do a partial water exchange, on a full day of fishing.
As far as converting a cooler, test how well the lid will be water tight. Many leak, and might need a thin tubing around edge to help seal. Guess who has tested some?

All the ones in our basement leaked. Also, if there isn't a latch, large water movement may pop the lid open.
If exchanging water via pail is too much of a hassle, a bilge pump on a hose would work for pumping water in and out.Doesn't hurt to have another spare bilge pump around.