Yes. Draw out a cube (or separate walls) of that size. Then try placing 12 x24 squares on that wall. You are going to have one whole tile in the center of each short end and 6” wide pieces on either side, or a 1 ft piece on one end. Do you like that look? You will have 2 and a half tiles on the long side. If you switch the orientation of the tile and put the narrow side down, you will either need to have the walls widened by the space of two grout lines, or have one side of one tile cut just a tiny (likely jagged) bit. Make sure your tiler can cut those edges well, because, the tiles being so big, the jagged edges become very obvious. When you have a busier wall of smaller tiles, they do not stick out so much. Only if you make the shower exactly the size of the tiles, plus the grout, and lay them in a vertical stack, will you get rid of cut edges. Play with layouts and see what you like. You can also consider Corian or Swanstone and have a life-long beautiful shower wall with no grout. Anywhere. If you vacuum or sweep regularly, a black floor can be nice. That is, unless you ever use powder. If you do not clean your floors regularly now, do not think about a solid dark color for the floor. Floors are not wet all the time, so their grout should not discolor. You can have more grout lines on a room floor than in the shower, without mold or mildew.

Id make my decision in this order. #1 quality and flatness of tile (this will decide if i stagger/stack. It will also decide how tight of a grout joint i can actually use .) #2 layout for best fit in the given space( accounting for expansion joints/grout joint size) #3 focal points (I.E. am I placing a recess niche in the wall? are there any windows i want balance with etc etc etc. Dont skip #1 #2 and dont force either/other. still make sure you nail #3

Contact the UK manufacturer and ask if they have a US distributor. http://blog.lauraashleyusa.com/get-inspired-with-tile/ https://www.tileshop.com/products/effect-black-ac-ceramic-wall-tile-11-x-11-in-496022?utm_source=google&utm_medium=organic&utm_content=surfaces_across_google&Kenshoo_IDA=PleaseAssignTagToAd&gclid=Cj0KCQiAgOefBhDgARIsAMhqXA5jCabvqF4kFNNEgnVjy6pudMw9VMLbWB7ixM9BnnbiCnvw6wuv4RAaAnsdEALw_wcB

Design-wise, it just depends on how it looks. Usually it's shiny on wall, matte on floor. But it doesn't have to be. Show the tiles you're considering and...well, people will probably STILL ignore your request and keep saying it's too slippery and not answer your question (even though you are aware of that and I think it is safe to assume you will not use it if it is not suitable in that regard)... anyway show the tiles and see if that helps people decide. There are normal things that are done, and you're not doing it the "normal" way, but that doesn't mean that your particular choices don't work that way.