I assume your TV is now wall mounted, which I think is much better than a huge cabinet. Cabinets designed for just this situation are available, or you could use an attractive bookcase. Remember that you will need ventilation for many of these components, especially the receiver, so don't put them in a drawer. In my TV room, I just stack the components on top of each other (with spacers to provide ventilation) on a small table.

I like your proposed arrangement. Looks like you could add a t.v. on a swivel mount with a small console underneath to the right of the fireplace. As a general rule, the rug under the dining table should be 4 feet wider and 4 feet longer than the table, so it seems an 8x10 would best suit the table when fully extended.

This is not your furniture I am guessing? You will want a real table, and need to find a place for it. You will get way better advice with a measured floor plan, and without it we're just throwing ideas around which might not work. But one of the problems is that your kitchen has many doors and openings, some of which are larger than they need to be. When you redesign your kitchen, don't forget that you can move doors much more easily than you can remove load-bearing walls. Reducing the size of the openings between rooms also gives you wall space in the kitchen, which is needed there. Here is one quick idea but obviously we need to know what's behind the walls etc. This gives you a door-less space in the kitchen for a table. Another idea is to have a table where there is now the china cabinet. That room now becomes the living-dining room, and the whole kitchen is available for cabinets. My son's house is arranged that way - no kitchen seating at all at table or counter but close proximity to a table in the living/dining room. Again, you may want to move the door between the kitchen and living room to an optimal place given your new kitchen design. You'd probably leave the door to the hallway from kitchen, in that case.

Can’t really tell from the pictures what your floor plan looks like. I would put it in the best viewing position if this is where you watch tv, which is usually opposite the couch. I think you have two choices, over the fireplace or in the bookcase, remove some shelves and have an outlet installed.