He is cuuute, and the video is adorable!

For his marking problems what about a belly band? You can buy them at stores and stuff but I know some people just use an ace bandage and wrap it around the dogs middle with a sanitary napkin in it. Less of a mess to clean up that way

The Boston sounds cute too though, best of luck!!!

Oh and five dogs isn't too bad And four of em would be small...so it would really only be like having 3 big dogs!