Yes, 2 cats are great!!! they will have each other and younger ones will adapt better to you, your home and your dog. I am also very glad that you plan to keep them indoors. I feel it is really a better option. I would add though that maybe more than 24 hours alone may be in order. You can tell by their amount of curiosity. Some need more time in a small area because a large area (an entire house) can be overwhelming. And introducing them to a resident pet should only be under supervision at first. You can always come here for answers to any questions. You'll get a lot of points of view. Can't wait to hear if you decide on them after you see them.