To revisit this topic -- for anyone searching for this combination using Google or the like....
The Greenlee punch set worked like a charm, just like it works with electrical boxes. Nice clean hole. The sink is an early 70's Eljay, very sturdy. Not sure of the gauge, but it's substantial.
Keeping the work well-oiled in the initial drilling seemed to help quite a bit.
(Now I have a sprayer on the lefthand side, like a southpaw engineer should!)