If you guys had to choose one black shoe that would be primarily worn with suits and wool pants, would it be:
Alden 9751 (black longwing on Barrie)
Alden 9741 (black balmoral shortwing on Tremont)
Leather Soul Alden black shortwing blucher on Barrie
FWIW, assume the buyer already has a black NST blucher for more casual outfits...
I thought that I might be able to help, as I wear suits on most days. To be frank, I am not excited about any of those pairs with a suit, as they are all, for a lack of a more descriptive word, clunky. I would recommend something that has a single leather sole and perhaps a less rounded, and more modern shape. I have a penchant for the plaza last, but the grant and aberdeen lasts can look sharp, too. I have to stress again though that single leather soles are critical.
Now, if by "suit" you mean separates or a wool flannel suit, then the Barrie / Tremont and double sole factors are more valid. But, and maybe this is my idiosyncrasies speaking, but I cannot think of an outfit -outside of a black wool flannel suit, which I don't even think exist- where I would wear more substantial black shoes over some shade of brown.