The cells of the enamel organ which differentiate into future ameloblasts are
Cells of inner enamel epithelium
Cells of outer enamel epithelium
Cells of stellate reticulum
Cells of stratum intermedium
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.