You will find the sword a peice of equipment that becomes cumbersome. I use a feild officers sword presented to me that belonged to comrade who past this life in battle.
I wear it only on the rarest occasions, ie: funerals, weddings, and the occassional Ladies Social where Officersare requested as escorts.
As for formal Dances and Grand Balls I recommend your purchase a sash and a proper belt for your rank. Dispence with your boots or atleast wear them under your trousers. White cotton gloves would be a must and reading on some 19th century ediquate would not be of a diservice.
As for swords if portraying a Federal Officer any Federal pattern will do. If Confederate then anything goes except the 1860 and later Federal swords. I suggest you look at Dr. Dammann's Civil War Medical Instruments and Equipment Volumes I, II, & III.