thought it best that

Which of the 2 choices does the bold part mean?

I thought it best to stay here. = I though that it was best to stay here. or I though that it would be best to stay here.

I thought it wise to stay here. = I though that it was wise to stay here. or I thought it would be wise to stay here.

Is this grammatical? He thought it best that I deal with it.

Which are correct?
He thought it would be best if I dealt with it.
He thought it would be best that I deal with it.
He thought it would be best that I dealt with it.
He thought it was best that I dealt with it.

Thanks in advance