I agree with Brandi Nashi Hicks on timber and colours - think about providing colour with things that are simple to change like cushions, artwork, rugs and other accessories while keeping the basics of your home neutral - this way you can quickly, cheaply and easily change the look of your home as new trends or your tastes change. Don't worry too much about storage for when children come - the way you actually live in an apartment can vary drastically from how you think you'll live in it so put in what you need now, and then adapt your apartment to your family. Babies and small children don't need a lot of stuff - especially if you share cots, prams, clothing with friends and family so that you've got only what you need at that particular time - this works until they're at least school aged and provides a win/win solution to you and friends on storage and cost of little ones. Your future home looks as though it'll be a beautiful happy place to be a family and I hope you'll be very happy in it.

Also love the buffet....it could be the "hero" of the room. It is beautiful and they are so hard to come by at a reasonable price. I have a much cheaper style mid century buffet and initially had the TV on top of it, but now the TV is wall mounted above it. The distance between the wall and the couch wall is about 4m and we have no issues with the TV being too high...you definitely need to factor that in if you wall mount it though...luckily I had a handyman friend helping me, otherwise I would have put the TV too high. With the TV being mounted, it actually makes the buffet more of a feature and anything that is put on the buffet is now "displayed" instead of being part of clutter with the TV. It looks great and I know yours will too if you wall mount the TV. That is the great thing about the mid century buffets...they seem to fit in just as well as modern furniture as they do with the classic furniture....and because your is "classic", it will never date...a great investment.

Before replacing your curtains as this can be quite expensive for such a large window, if they are in good condition, add a band of extra fabric to the bottom in what ever suits you, your existing curtain track can then be moved up to the ceiling for good looking full length curtains without the large round eyelets, could save you a lot of money, I would look at replacing/removing the sheers cheers

You are right - leather is the go. You could combine a soft and mid grey, or bone and tan, depending on what palette you like. You are looking for the 2 sofas to relate to each other rather than matchy matchy? My preferred look too. You could use the same sofa in different shades, that's an easy get together. Or decide on one being more of a standout - like a mid century style wooden sofa with leather cushions, and then keep the other one simple. The top photo is that mid century style and the bottom shows a sofa that would coordinate with it. (similar wood legs and square edges). I know it's in fabric but it comes in leather. And it shows you what 2 of the same sofa in different colours would look like (both leather of course).