Such a one

[Xinfu]

-The most important quality that a president needs is ability, not outward appearance or his face. A handsome president is useless. We do not need such one.

-[...] We do not need such a one.

Are they all correct English sentences?

[Rusty]

We don't need such. :good:
We don't need such a one. :good:

We don't need such one. :bad:

[Xinfu]

Thank you.