If I were you I would go for the Ghost chestplate. At lvl 500+ you will never get headshot there with a sio, and with the changes you need to kill there as fast as possible, so the extra distance the Ghost chestplate gives is super welcome.
But I Guess the best would be you to try both, 1h each one, and check which one works better for you. For sure you won't die with any of them.