Have you taken a look at BierMuncher's Cream of 3 Crops? https://www.homebrewtalk.com/f62/cream-three-crops-cream-ale-66503/ (71% 2-row, 23% Corn, 6% rice). My personal approach to his recipe is 63% 2-row, 18% flaked corn and 18% flaked rice. 150 mash for 90 minutes. Galena for bittering...