Hi and welcome to TFP! Full tiled any thing is few and far between unfortunately. I LOVE tiled pools! They are so pretty!
I have seen where someone put "rock" on their shelf to make it look more beach like. I cannot find that thread right now. I will keep looking though. There are a couple who make their shelf a "sand" color to make it look like a beach also.
You installers will need to be top notch to make sure the tiles are even and flat. Sure do not want one a corner to be a bit raised and scoot across it on your bum and it scratching you.
I do worry about how slippery it might be though. I would see about getting a sheet of the tile you are thinking about using and putting it in your tub to see how slippery it is.