I use my cell number as my professional contact. I use Google Voice (free) as my personal contact information. I route the calls to go directly to my cell. That way I'm only carrying around one phone, and I'm not paying a fortune for the privilege.
I use a single phone for everything. My way of organizing things would be arranging the applications according to their type. Emails and messenger apps are grouped similarly with software for video conferences. It makes it easier to focus on the task at hand.