I have a Graco Pack N Play for Calvin that I only use for time outs (when he would be mean to Chase or visiting dogs) and for when they get bullys since he is possesive of his. When we are at work, they each have an ex-pen with their beds, potty pads, and water. I have 2 of these
Marshall Ferret Playpen 11 Panel - Ferret.com. I like these because the panels are higher than some of the dog ones, and you can get the cover if you have a climber.