Quite can be used with a/an + noun. Before a noun with a gradable adjective, we use quite a/an.

It was quite a pleasant experience. (NOT It was a quite pleasant experience.)

Quite a/an is also used before a noun with no adjective.

The party was quite a success.
She is quite a woman!

Before a noun with a non-gradable adjective, we use a quite.

It was a quite perfect evening. (NOT It was quite a perfect evening.) (Perfect is a non-gradable adjective.)

Rather can be followed by an article + noun.

He is rather a fool.
That’s rather the impression I had.

Before a noun with an adjective, we can use a rather or rather a.

She had rather a good idea. OR She had a rather good idea.

So can be followed by an adjective + a/an + singular countable noun. Note that this is a rather formal structure.

We have never seen so good a boy. (NOT We have never seen a so good boy.)
He was so big a man that he could not sit in that chair. (NOT He was a so big man …) (NOT He was so big man…)
I have never before met so gentle a person.

Note that this structure is not possible without an article. If there is no article, we use such, not so.

It is such terrible weather. (NOT It is so terrible weather.)