I love the godmorgan sink for their clever plumbing moving the ptrap to the back so that you can have drawers. I got one but my plumber threw up all over it for the cheap quality of the plastic in the plumbing. He did agree about the design and is building ours with the ptrap in the back so that we can do drawers using better quality stock parts. Mirrors.. I would suggest picking this first as this will drive much tile you need. Have you looked at IKEA mirrors. They are a good price point. Also home goods etc.. Faucet.. Online prices are much better.. Do you like the look of the faucet in the picture? I went with a simple version from a good quality brand for my regular bathrooms with a single lever. For powder room, I also wanted it to be fun and did wall mounted in antique copper.

I would say the rough in box will be about 4" round. Then it depends on the size of fixture you select. My fixture is 5" wide and I have them sitting about 5" from the mirror on each side. But it could sit a bit closer.

I really like the wallpaper and the bead board. For a counter, perhaps consider wood - butcher block or just planks of pine or something. It will bring an amazing amount of warmth to your space. I did it for my kitchen counter when I reno'd 8 years ago and never tired of it or regretted it. It's cheaper than most other options, biodegradable when someone else reno's and it goes into a landfill, easily refinished if it needed at some point, and gives you some sink flexibility. I really like square or rectangular sinks better than round/oval. And I think that's probably easier to cut/fit than other shapes. And can undermount it. Those vessel sinks look nice, but they become so high that they are less user friendly unless you build/alter your cabinet to be lower height than normal... If you get your hubby to agree to doing the floor, I'd choose wood there too. No grout lines to clean. Washes up easily. Different if you have a bath/shower in there... Oh, and I think for a small space like that, pretty economical too... Just doing go with the engineered stuff - no where near as durable or attractive.

Ttt