I agree those are lovely pens, but you can use all sorts of things to confine broody hens with their chicks. While they're brooding they primarily need to be kept safe, dry, & secluded, with just a bit of space to scratch, dust bathe & poop, with food & water always available. Once the chicks are hatched they'll want more room to roam, to scratch up food for their babies & dust bathe.
I've had hens brood in rabbit cages, dog kennels, fenced-off corners of pens, and in special little arks/tractors. I just like to have them separated so they won't get confused while out on their breaks & return to a different nest, letting their own eggs go cold. And also so other hens won't intrude on the broody to lay their eggs in there.