Fish box pump question?

My '91 V-20 has an insulated fish box in the floor between the seats. I would like to use it as a fish box and not just storage. Since the pump would have to be mounted higher than the bottom of the box I would need some type of self priming pump. Would I need a macerator pump for this application? Does anyone on this board use the fish box for fish, if so, how do you get rid of the water, scales, blood etc.? I have a switch on the dash that would operate a pump but when I got the boat there was no pump installed. Thanks for your help. Barry