I'm tellin' ya... Cold Room... you will be incredibly thankful you did it.
Keep any kegs you'll have on tap in it... lager in it... hell, use it as a second refridgerator if you need to.
I have a little DIY walk-in and it's a REALLY nice thing to have.
Like I was posting before, a bunch of guys on HBT have built them with nothing more than a good amount of insulation, a regular wall-unit AC and some ingenuity.