Ergonomics? Get a wheelgun!
Since this is the general handgun forum, I'd say it will surely be a revolver first. They are much simpler and smoother to operate than semiautomatics.
Then I'd narrow it a bit to a nice L-frame or N-frame S&W, with a 3-6 inch barrel... 686, 625, 627... all very easy, precise operations, and smooth and accurate shooting.