I am going to get a Navy double breasted over coat made and was wondering as to the best size for the buttons on front. RJ Weldon is the only place that I seem to be able to locate them so am limited to their sizes. The two that I am in between are 40l or 45l.
Which one would be appropriate?
I've attached a picture that I might try to model the overcoat after.

Which one would be appropriate?
I've attached a picture that I might try to model the overcoat after.





