I leave the big rolling unit in one place.

Have you considered a cleaning cart? The commercial Rubbermaid stuff is pretty durable. Rubbermaid Commercial Products - Rubbermaid Cleaning : Cleaning Carts

But you know this is the one you want: fridge, MP3 hookup for stereo http://www.lowes.com/pd_112374-55738-LWTB08-5319D_0__?productId=1119495