From what I have read NASA has opted for the 4 seat version only, and then placed cargo under them where the other 3 seats would be. SpaceX has designed the capsule to carry 7 if you want an all passenger config but it will need to be heading to a destination fairly quickly as it doesn't leave much space left over. That said, even at 7 it looks like it would still be roomier than a Soyuz at 3 people.