Architect here. Our master bath is 6’-4” x 12’-0”, so similar size, but different layout. No linen closet (I store towels under the vanity). I love our walk in shower with just a handheld shower that can be adjusted to any height. The shower area is 3 ft wide by 6 ft and feels almost too long. I used plain white subway tiles on the walls and an inexpensive mosaic floor from Home Depot. I got a nice border of glass tiles, and chair rail tile installed at about 7 feet high. The recess for the shampoo and soap also is fancy tile. New shower heads may not give you your old water pressure as regulations have changed.
I wish I’d splurged on a toilet with a bidet. No easy way to install it now as there isn’t even a plug nearby. I also wish the toilet was behind a door. We ended up sticking with one sink since we rarely use the bathroom at the same time. I like the Toto toilets. I also wish that I’d remembered to install reinforcing where we might want to install future grab bars or a pull down bench.
It’s impossible to photograph, but you can sort of get an idea here:
Around here a down to the studs remodel requires a building permit and an architect. Your architect can help you with materials or you can come to them with a pretty clear idea of what you want. They’ll know what clearances are required. (Space in front of a toilet, minimum height of tile in shower area, required space in front of a sink and the like.) If you need one ask around who is good and easy to work with.
For ideas I’d spend a couple of weekends browsing show room looking at tiles and fixtures and asking lots of questions.