Yes, you will want to make sure the beer stays cold in those lines, otherwise the first 1/2-1 pint will be warm foam before each session, and seeing that you only drink 1 a night, this would mean a lot of lost beer!
I really doubt a liquid cooling solution would be practical for 2 feet. Most people use them for long runs (to their keg room for example)
You are going to want to get a blower to blow cool air in the box through some tubing, and insulate the box well well. You can make our own blower using a project box and a pc fan as well, but it wont be as efficient. Make sure you have a return tube as well so that you have a path for the air to circulate.