Are you still interest in tank info? What do you plan to keep?
In general, most people on lake Cumberland have gone away from water pump filtration or aeration systems and so have I. The idea is they beat your bait up too much. I have a greyline and it is built like a tank but have pulled the filtration box, which takes a 30 gallon tank to 45. greyline does a moderate job of maintaining cooler water in the summer. It's a trade off... Tank diameter to how much insulation you get. I do not actually use the Greyline in the boat any longer. I use it on the dock as a secondary holding area for extra bait. It just did not fit in my new boat as well.
This is what I have on my boat now:
http://www.ebay.com/itm/Keepalive-Ae...item2811083e1a
It just fits where I need it to be the best. Insulation is OK.
An option, which I have not done yet is to build a "blanket" that you use only when it's really hot out.
Notice the common word... Insulated.