How does he drink his scotch?

If with ice, go with a rocks glass and throw in a round ice maker.

If he drinks it neat or with a little water, go with the Glencarin glasses everyone is recommending. They are my go to. Another solid choice in this vein would be a copita nosing glass. They're basically a Glencairn on a stick.

Whatever you choose, Amazon or Waterford, a nice touch would be getting the glassware engraved.