Igloo makes a 60 quart "Ice Cube" cooler that happens to fit a carboy or bucket quite well: http://www.igloo-store.com/detail/IGL+ICECUBE+60+RLR
(ignore the price shown, your local wally has it for less than $30)
I dedicated mine to my carboy and cut a hole in the top for it to stick out of. Other folks have custom-cut some styrofoam and left the lid intact. You can use frozen ice bottles fit into the corners to keep temperature down, with or without the carboy sitting in water.
Or you can enhance that situation by using a temperature controller, a cheap pond pump and an immersion chiller (or loop of copper tubing) sitting in a ice-bottle bath in another cooler sitting nearby - works great, all you have to do is swap an ice bottle twice a day 2nd cooler.