I bought this from Austin Home Brew: http://www.austinhomebrew.com/product_info.php?products_id=10644
I then un-coiled my 50 feet of 3/8 inch OD copper tubing, measured and cut a 25 foot piece. I am thinking about using the other 25 feet for a pre-chiller / Emerson Chiller. The ground water is pretty warm here in the summer. I also cut 24 feet of garden hose.
Then I coiled it around a 10 gal corny keg
Then I put the ends on and loosely zip stripped it together.
Next thing is to test it and make sure everything is water tight. Looks like it passes!