We have AC at home so I never run my Vino. If the location you are putting the humidor stays under 75° you should be fine without the cooling unit.
The big plus with the Wine Coolers is that they generally seal real well, unlike many cabinet humidors.
If you are just looking to add capacity and "looks" don't matter much and the ambient environment stays under 75° I would recommend a basic cooler (Coleman/Igloo, etc.) or two (or three
).