Tall units up to the ceiling can look very nice, although would function as displays mostly. Honestly standard height kitchen wall units wouldn't concern me, they might accentuate the height which is not a bad thing at all. Alternatively if you have enough storage in the base units why not skip wall units altogether? Open shelves or even nothing, just a stunning splashback

You're the customer so have it how you want. Its more expensive to tile wall to wall which is why lots of kitchens are only tiled up to the legs, but its getting more and more popular to have the kitchen fully tiled before fitting like they do on the continent. When we have a kitchen to fit and its been tiled we lay hardboard over the floor to protect it, so it is an extra small cost. Accidents can happen though like dropping the oven but that could of been an old existing tiled floor that could be chipped and no replacement tiles available. Also its harder for your fitter to install as he has to scribe and seal all your decor panels to the floor when its been tiled is another reason installers prefer it to be tiled afterwards.

That’s good they will give you a sample. Had a quick look on their website and it looks a beautiful colour and I can see your dilemma. It has a grey-brown hue similar to F&B’s Mouses Back, well on my screen anyway! Were you able to view a kitchen, or at least a door, in it? Im not sure I would choose a kitchen just from a photo. Second photo is F&B’s Mouses Back.

Make a list of the storage thats there. Measure the size of the room and draw some elevations showing the position of windows, sockets etc. Decide on a budget. If you take this information to a kitchen retailer they will often draw you a free layout and then you will get a much better idea of cost, appliances etc. Try not to change oven and sink positions and the cost will be lower. It must be hard to cook on the freestanding oven without a set down area next to it for example.