Looking on the internet deeply has found these results:

such a good person is the most popular phrase on the web.

so good a person 11,950,000 results on the web	such a good person 112,500,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I worry that maybe I'm not as good a person as you are. Just... I mean, if we got married now, I would make your life miserable, and... you are far too good a person for that. But I would never say you weren't as good a person as she is. I know you are too good a person to feel that way. Back at the Crab Shack, Joy was getting desperate to prove she was as good a person as Darnell. It sounds so good coming from a young person. You can't be that good a person and well adjusted. You're too good a person to understand that, Gracie.	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

so good a person

11,950,000 results on the web

such a good person

112,500,000 results on the web

More popular!

I worry that maybe I'm not as good a person as you are.
Just... I mean, if we got married now, I would make your life miserable, and... you are far too good a person for that.
But I would never say you weren't as good a person as she is.
I know you are too good a person to feel that way.
Back at the Crab Shack, Joy was getting desperate to prove she was as good a person as Darnell.
It sounds so good coming from a young person.
You can't be that good a person and well adjusted.
You're too good a person to understand that, Gracie.

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.