Can you show us a picture of what you've chosen? It is real marble, or a porcelain look alike?

you asked about shower floor tile, what is the shower wall tile?

The first picture is the bathroom tile in a honed marble tile and the second picture is the shower wall tile( not marble ).

These are some samples that I currently have

Can you include source info on the wall tile? Like the producer and product name.

It is produced by Emilceramica and it is called tele di marmo white paradise

Based on posts on this forum that I've read over the years, you don't want real marble on a shower floor. I also used real marble on a bathroom floor I remodeled almost 15 years ago and regretted it. If any males use the facilities and have bad aim you will get etching. But if you think marble will work for you on the floor in general, look for a porcelain tile for the shower floor that has the gray in it similar to the floor in a simpler pattern than what you're showing. While you do want a small format tile to aid drainage, some of the ones you're showing are too small and will give you a lot of grout to clean. This is similar to what I used in last bath I remodeled:

Modernized Master Bathroom · More Info

If your pattern in the flloor is large do a smaller scale pattern in the shower, just remember white grout in a small scale design gets dirty looking fast from dirty feet in the shower.

i think a smaller scale mosaic (non marble with a mid tone gray grout will look good)