buckle for a belted plaid

[Guinach]

Hello,
Got a quick question. I'm putting together an outfit for the '45.
I have two nice 4yard plaids and a small section for hose.
I'm looking at belt options. I was wondering if a square or fancy silver buckle would be appropriate.

or a fancy one

This is being advertised as a belt buckle, but it looks like a shoe buckle.
The other is a belt or sash buckle, that might also be good for a baldric. Any thoughts?
How wide? I'm thinking about 2.5 or 3 inches.

Thanks for your input.
Kon G.
Appins