I don't get why you would want any another instrument given that the futures will provide you almost 17 hour a day access to your orders and not be as prone to gap and rebalancing risk as an ETF would be.
Margin requirement overnight and the tick size in terms of movement, so 5 points/1 tick is ~ $30 move similar to /ZB. If my entry is not close to perfect, I would get stopped out too fast. Or I am sleeping and overnight something happens in which I am not monitoring what happens to my stop.
Whereas with a Nikkei 225 put, my maximum risk is set in stone, and even if I lose the premium, I am fine because I believe in the trade that much.
Sadface, Nikkei down 2% already overnight.