OK, I've reread all(I think) of your posts now and I see your point about the wainscotting not really being truly visible in such a small space. You have options, but I really think the wood plank is not the way you should go, it is very far from what was your original inspiration. I am not sure it will make you happy. I think I would do the wainscotting, scaled down to fit the space. Layout/draw specifically the layout for each wall segment, the 36' toilet wall, the long wall next to the toilet, the sink wall. This is homework that will make the difference. The marble inset band needs to be fairly wide, maybe 6", it would be just at the level of the sinktop. Carry the marble band around the pony wall endcap, you could continue it around the shower, but I think you said you didnt want to. Top the pony wall with a marble sill. My only doubt in the cohesiveness, the peacefulness of this plan, is the two cabinets you want to put over the toilet(assuming I am remembering that correctly), I think they will make it heavy. So I would want to hold off on those until the space is complete and then decide. I think a chrome(I am assuming your finish is chrome) train shelf might be better to hold towels, yes it will not provide as much storage but perhaps it could do. I think this gives you the classic look you were inspired by.

unless you get the expensive glass tile that has no green tint, any white glass tile will take on a very cool greenish/blue tint. It's just the way glass is made. I used a 4x12 white tile in my shower (which is very large). It's not a big deal to clean (the upper half never even gets wet) If you want to match that marble looking tile, then do white porcelain or ceramic tile. White glass will not compliment that marble. It will look too greenish.

Colour variation from a Big Box store marble tile is to be expected. Sorry but they take returns = different batches. Colours run 'true' from one area of the mine. If you have two different marble blocks (5 tonnes of marble being blown off the side of a mountain at a time) from two different areas/levels of the mine, you can and will have different colours. Most of the marble from HD is from China. That can mean multiple mines many miles apart. Your purchase did NOT have a skilled professional picking the right amount of tile from the same batch. This is 'Tony' pulling boxes out of a warehouse for minimum wage. Because HD takes returns...go ahead and take them back. Feel free to work with a stone/tile company or go to a kitchen/bath company to help you pick out the right AMOUNT of product from their stock. What is the marble being used for? Do you know most marbles need to be sealed? Up to 3 times at time of install?

Raimondi, what plain white top do you suggest? This is supposed to be for advice and ideas. I am happy to try to use Trivets etc but with a big family, or house guests helping in kitchen, you never know if there will ever be an accident eventually. the more resilient, the better.. I am seeking information to learn about it and decide quickly. I see you are a pro. what do you suggest? We cook a lot, so it doesn't matter to us if "that"crowd does not. (I assume you mean the modern crowd) I was hoping someone owns this Lapitech. We wanted quartzite slab but it felt too busy so we are looking for a simple white top at this point. Thanks.