The cells of the enamel organ which differentiate into future ameloblasts are
Fate of various cells in enamel organ: 

Inner enamel epithelium — differentiate into ameloblasts
Stellate reticulum — collapses and does not exist
Outer enamel epithelium — cells flattens and thrown into folds.
Cells of inner enamel epithelium
Cells of outer enamel epithelium
Cells of stellate reticulum
Cells of stratum intermedium