The phrase "either to be" is correct and usable in written English.
You can use it to introduce a pair of contrasting choices. For example: "I must decide either to be patient or to act now."
He added, "The drawings had either to be made by Galileo himself or with his supervision".
It took until September for either to be reinstated and backdated.
To be a pedestrian here is either to be bold or to be poor.
This is either to be America's Era of Enlightenment or Entrenchment.
I can't imagine either to be content closing out their time with the national team with the silver.
He doesn't understand why – I don't quite either, to be honest, and I'm not as drunk as he is.
It needs either to be more layered or to take its satirical pose further and make it funnier.
But to find such a planet, astronomers needed either to be very lucky or to know where to look.
The plaintiffs were asking either to be allowed out on parole or to have the conditions of their incarceration changed.
Every forecast about the future of the internet has, more or less, turned out either to be an outrageous underestimate or a hopeless overestimate.
