I think this is to easy for a persons of your intelegance.
http://www.amdzone.com/articleimages...ammerclose.jpg
I want to see you do it to one of those!!!!
Seriously though I am not sure this is a good idea or not. If you run chilled water back there you are going to somehow need to water proof things back there. But I think you could use one of them small fish tank pumps for the pump. Sure do not want to use a 370gph one.