Starting an eight-test tour, with more matches in England, Ireland and Wales, it will be Smith's third UK trip, and second as a New Zealand team member, but it is the first Northern Hemisphere experience for Coster, who has, however, shorn against Australia.
Smith, who is married to fellow world record-breaking shearer Ingrid Baynes, was in all-conquering post-Christmas form locally, winning 15 finals, including the two major events.
Coster, former three-times winner of the PGG Wrightson National, New Zealand's premier multi-breeds title, won his place in the team with victory in Te Kuiti's New Zealand Shears Circuit final in April, and won six other finals in the South Island earlier in the season, including Canterbury.
Scotland is expected to be represented by Hamish Mitchell and world champion Gavin Mutch, to whom Smith finished third in the Scottish blackface final at Lochearnhead two years ago.
The team's itinerary is: June 29-30, Lochearnhead Shears, Scotland; July 6, Lakeland Shears, England; July 9-11, Great Yorkshire Show, England; July 13, Rickamore Shears, Ireland; July 19, Cothi Shears, Wales; July 20, Lampeter Shears, Wales; July 22-25, Royal Welsh Show; July 26-27, Corwen Shears, Wales.