Although I could never share a sink with DH, in a bathroom the size of the OP’s, I would grit my teeth and opt for the single sink for more counter space. I’d also suggest the largest LED mirror that would fit in the space. They are inexpensive, and not only do they remove shadows (great for hair and makeup), they light up the room more than you’d expect.
Also, if you’re going down to the studs, you might consider rearranging the galley-style layout you described (wet wall with tub shower on one side, dry wall with vanity/closet on the other) to place the new shower-only against the whole back 8’ wall which will enable you to have a spacious one. Like the one shown in the link, I also like wall niches for bottles instead of shelves or over-the-showerhead caddies.
You might also consider a pocket door so you can take better advantage of all the interior space.
So I’m guessing that none of the suggestions in your earlier Help Me Remodel My Master Bath thread helped get you started?