blancaharo, I like both of those buffets and either would work with the new dining set you're getting. I would probably choose the second mid century sideboard assuming your wishbone chairs will be a similar wood.

You will need to change out the chandelier to finish the look. Be sure you hang it lower than the current one is. It should be 32 - 36" above the table.

I agree with groveraxle, both buffets would look great and I also like the wooden one a bit more with the chairs. New lamp and some large art and your room will be great. Very trendy.

I like the white one

I love the white one, but agree the second one would coordinate better with the wishbone chairs.

The 2nd one

Personally, I like the second one better, but if you paint the room the dark charcoal, the white one would probably look better. I'm not sure how I feel about white parchment with Cararra marble, however. If it is a very high-end parchment finish, it should be fine.