In addition to the Esterbrook, Waterman made a "Clergy" pen in the '40's. Check out pen 1611 on David Isaacson's site (on
this page.)
Even though these pens aren't cheap, the Holy Water Sprinklers are going to be far more expensive. I've seen models based on the Parker Vacumatic and made by LeBoeuf, but they are rare and pricey.
Best regards, greg
(edited to fix hyperlink)