OK. So you've got the start to finish 'cow art' on the walls. Either dining room or kitchen is appropriate but don't have anyone over for dinner that is squeamish or a vegan.
It's great that you're adopting a greyhound. Very nice dogs. I had afghans and both are sight hounds and their demeanors are very similar. Both have a reputation for wanting to run (and at times they do) but they are gentle and loving and, basically, big couch potatoes. Nice choice.