Bar blenders with enough torque for crushed ice, not just soft fruit. A domestic jug motor stalls on a frozen margarita by the third order; these run margaritas and daiquiris through a full service.
A high-torque motor and tough jar that handle frozen drinks and crushed ice repeatedly without stalling or overheating.
A commercial bar blender is built for it; domestic blenders aren't. We'll point you to a model rated for your volume.
A busy frozen-drink bar often runs two so one is always free. Tell us your peak and we'll advise.