Walmart.com: Pet Gear Octagon Pet Pen with Removable Top in Sage: Dogs
this is what I use, it has a roof on it and a floor. But I don't know how well two will fit in it, you'd probably have to get the big size (I only have one so I have the small one). I use it mostly for travel, but set it up in the house every once in a while for Harley to play in. (He has his own room with a baby gate for most of the time).