What is the proper ratio of heavy cream to chocolate for a thick ganache?
Normal ganache is 1:1 indeed. You can make a more caramelly one by adding honey and butter:
try 14 oz cream, 12 oz chocolate, 2 oz honey, 6 oz butter diced into small cubes.

Boil the cream and honey together, pour over the chocolate, stir until melted, melt in the butter.