Yep cast iron best way to go here, just treat your stuff right, no soap or if after you HAVE soap it, heat it and oil it up again.
We have two, one flat skillet purchased about 10 years ago in El Canal with my first wife so she could make roti and in the other a standard 12" fry skillet at Price Mart about three years ago for RD1,600.00. When Price Mart had them they had a bunch and I remeber I was going to buy another the next week they were all gone.....I have not seen them since, but have not really looked latly.
I have seen the enameled roasters at SEMA in Herrera.