Elite cells are good, if you wanted to go lipo, orion/peak have the 3200 and 3600 2s packs that are shaped to fit in those trays. I run a 3200 2s orion in my m03 that has a similar tray. Those lipos use kokam cells, and can push pretty hard. Run that and a 7700 mamba setup and the me16 will be fast....