Is a jacket ot suit required for Shacharit if you are already wearing a tallis godol?
No.
I know that one should daven Shmone Esrai wearing clothing fit to go visiting with a king or other important person. This would mandate a jacket or suit to be worn by
Thats a true statement but incorrectly applied. That is, according to that reasoning you should upgrade and exclusively wear your shabbos finery at each prayer. And surely you have never seen that. The intention here is that one realize he is standing in front of the King of kings and act and dress accordingly. Surely not with soiled or ripped clothing and not in a manner that is disrespectful to the king. Each person according to his level. The Rav wears only a Talis for shachris with no jacket. But for Mincha and maariv he wears his hat and Rabbinic coat as befitting his stature as a Rav, and therefore also wears it when he prays.
A story is told of the Gaon, Rav Yaakov Kaminetzky, who would visit his children from time to time in Baltimore.
He was seen taking a walk once in the street without his Rabbinic garb, and someone was brazen enough to ask him why?
He answered that in New York I am a Rosh Yeshiva, and need to dress the part, but here in Baltimore I’m “just” a Zaidy visiting my grandchildren.
It is not clear from the discussion what is the requirement for the general population whether you need to wear a jacket and hat for Mincha and Maariv…(when one is not wearing a Talit Godol.).
Abie
One is not required to wear a hat and jacket.