For what you want I wouldn't be going to too much trouble. The unit uses about 12W max so I'd find yourself a little enclosure like my pic I found. Plastic lids are very easy to work with, and if you don't have precise machinery to machine the hole, you can easily do it carefully with a jigsaw. Put some duct tape on where you're cutting to protect the surface that will remain. For power I'd simply use an external plug pack, and run the lead through a nylon gland on the side of the box. Same goes for your ethernet connection, use a gland big enough to let you run a standard ready made patch lead through of the right length. Your location will dictate where you get this stuff, all of it can normally be found at any decent electricians' supplies store, or a hobby electronics type place.
cheers, Aus