This has me thinking you would get very good temps with a car radiator.
I was looking at this site here
http://www.frigair.com/index_en.html i only had a very quick look the first i seen was a rad from an Alpha 75 this has a surface area of 410*440*38 and is made from copper and brass . You could have this at the side of your case might not look very pretty but would do the job well.