It's hard to make a hen go broody, but generally, leaving eggs in the nest should/may trigger the urge. You can leave fake eggs or golf balls in the nest if you don't want to waste eggs. If you search the forum, there are lots of posts on broody hens and hatching.
I have nipple waterers hung from a 1"x1" that I cut a notch in the box to accommodate. And then there's a 2"x1" running low across the brooder as a training perch.
I love the window idea! I bet that would help them be less spooked.