I would similar to to know what type of professional could drill a earthenware sink and put together a hole for a touch? ...

Having shower problems.. (water leak)?
Answers:    A plumber or tiler should have the earthen or diamond holesaw required. First check that there is not a hole partly cut out through the underside, if so punch it down from the top.
Is it possible to tile over drywall to...
either a kitchen fitter/joiner or a plumber should confidently cope with this errand.