Yes they exist, and a simple google search yielded many promising results. A $260 RooR was at the top of the list, with others further down the page.
umm shitloaf has a fixed stem showerhead beaker. I wanna say he got it from soulshinefamilyglass on etsy, but im just guessing. Heres a vid of his.
Its always good to do your own research first however, so that when you propose your querry you have some samples to lay on the table.