Check the size of the design on that first fabric as opposed to the size of your seat. Will one design repeat fit on the chair? Or will you be losing part of it?

Yes I understand the chairs can be bought separately. Is there a specific style you like? Have you seen these at Crate and Barrel. Really pretty and could could update your space I love pottery barn chairs too. They are made solid and sturdy. They worked for us when our children were small.

The wishbone chairs work better as captain's chairs but still three different seating options is one too much and the black is the odd man out. The bench does seem misused here as they are most effective or 'well' used when there is no room for the movement/space a chair requires. Your guests would prefer a chair. I can see how the wish bone melds with the rest of your decor but I really don't see them working with the other chairs in the dining room. Either or, I think would look best.

I think that tall back windsor style chairs can have a lot of look around a 48" table and will make it feel too cramped. Look at pics of them with 4 around a table and see what the size room looks like. I too think the chandelier is a bit too big but it is ok because the arms are slender. I think if you pair it with all the spindles in a windsor chair, that area is going to start looking like a bar code! Also, given that your husband is a large man, I would absolutely not get a cheap chair you have to assemble. Go to a store where you can sit on them and feel what they are like for both comfort and quality. And pay attention to the width of the seat no matter what chair you get.