What's the style that you like? Maybe share a few pictures of the lights you've chosen for other spaces, and the ones you've found that you like but aren't the right scale?

Where do you plan on hanging the single light over the dining/living area? If you don't want two fixtures, I'd strongly recommend hanging it over one of the areas and just forgoing a fixture in the second area (rather than hanging it halfway between the two). If you hang it halfway between the two, it will look "off."

When thinking about lighting and controls, there's three types to consider: 1) Task lighting, which is lighting designed and focused for a specific task in a specific location. Recessed "can" lights may be used for this if properly located. Other types of fixtures may also be appropriate if carefully chosen and located; 2) Ambient lighting, which is for raising and maintaining the overall lighting in an area to some desirable level. These lights may or may not be visible, as in the case of cove lighting and other types; 3) Feature lighting is generally used simply for the eye to see and focus on a "warm" lighting source as part of the interior design of a space. Such lights may not provide much direct illumination, but rather just add a glow and appeal to an interior space.

I would not recommend "only one big light in the center of the living/dining combined room", since it's unlikely that it will look or function well, in either the living or dining room. It will most likely remind you of a Motel 6 room.

Since you will have a pendant over the island, using side tables, adjacent to seating, with matching light fixtures, can easily provide the "feature" lighting in the living area. These can be aided by carefully positioned recessed ceiling lights for the coffee table and wall washers for the wall with TV and other items.

You will certainly need lighting for the dining table. Two or more recessed ceiling fixtures will work fine.

Putting all the ceiling and wall fixtures on adjustable rheostat controls will be a big help for different lighting intensities. Good luck with your project.

Agree with Virgil , check out this Youtube video, and it should help you to visualize Virgil's idea.