Structural beam advice post chimney removal

I am in the process of removing a fireplace from a bungalow. The fireplace divides the living room from the dining room. The ceilings in both rooms are vaulted, and the beam from each one goes into the back and the front of the fireplace. The beams do not connect to each other, are supported by the fireplace, and are probably 18-24 inches apart.

I am looking for some advice on supporting the beams/roof once the fireplace has been removed. I am also interested in options for the other end of the dining room beam as it sits on a wall that I would like to remove. I have ambitious plans about opening up this area, and want to make sure I make the right choices