Are you planning on keeping it in the house?

I threw out what I used in my current Journal article: I put them in a small nest box made out of cardboard that I move them around in. I soon put that in a soft sided pet crate commonly sold at any pet supply store. They are cheap. They have mesh sides that stop most of the mutes. From there, I go to an imprint tank / box that is fairly large. They can be made on the cheap like mine, or made very nice, like Harry's. From there, I tie them on a shelf perch in the living room. I keep cheap outdoor carpeting spread around for the "overspray."

There is no real containment proof system when it comes to goshawks in the house. It's something I put up with until cool weather comes. I find that you pay a little now, keeping them indoors, or, pay a lot later and possibly forever for not. The messy part will pass soon enough. In 3 or 4 years you will find and remove the last remnants of floating down. LOL

Having said that, I'm sure that some others deploy a system where the bird is kept in the house little or none at all. That used to be my system many years ago but I've come to prefer the house method.