OK... I have a question for you Kegerator engineers.

If I put a 15cfm blower in the bottom of the Kegerator, just how far up the tower should I run the hose? I have a Danby Kegerator (I have almost as much in modifications to make this thing work right as I did to buy it!!)
One other question.....
My MGD Pony keg has a rubber coating on it, will that make it harder to cool?
Thanks,
B-B