who is old enough/old enough

Which is correct?

1. He is a guy who is old enough to make this decision.
2. He is a guy old enough to make this decision.

The examples are mine.

Of the two, I'd use the first, if I had to use one of them at all. However, I'm not sure I see the need for "a guy". You've used the pronoun "he" so the gender of the person is already clear.

He's old enough to make this decision.

@Vladv1 Please correct the misspelled word in your title.