For customizing the suit energy usage, you could have the ability to use a large or small amount of energy in armor mode or cloak.
Such as:
25% Armor - Faster movement, less energy drain, but less bullet resistance.
200% Armor - Almost no movement, 1 second life span, almost invulnerable.
25% Cloak - Less energy drain, relatively easy to see from far distance.
200% Cloak - Extreme energy drain, 2-3 second life span, completely INVISIBLE. - no shadow, or light bending.