Need a belt for a balanced look, except when wearing a vest or loose sweater.

For a nice, inexpensive casual belt, buy a 2" tool belt from HD or Lowes. They are undyed veg-tan, shorten to fit you belts. Get some black or brown leather dye at a leather store or hobby store. 2 coats of dye, some buffing, and perhaps a bit of neutral polish and you're good to go.