Sakashima's Will

Choosing a token won't cause other nontoken creatures you control to become tokens. If you choose a nontoken creature, other creature tokens you control won't stop being tokens.

Sakashima's Will copies the printed values of the chosen creature. It won't copy any counters on that creature or any effects that have changed its power, toughness, types, color, and so on. Notably, it won't copy effects that made the chosen creature become a creature if it isn't normally a creature. For example, if you choose a land that's become a creature, all your other creatures will become noncreature lands until end of turn.

Once you've chosen both modes for the spell, it doesn't matter whether you continue to control a commander. This is true even if you somehow no longer control a commander as you finish casting the spell.