The store with the best selection at this late point in the season would be our store On Rt. 20 in Westmere. This is a mile or so past the Rt 20 entrance to Crossgates Mall. They have, at this moment, 10 Bar Harbor Junipers which get 10″ tall. 14 Blue Star junipers butthey might be larger than you want. They also have 11 Green Mound Junipers which makes an excellent groundcover but is only about 8″ tall.
Planting now is fine but the selection is much better in early May. Spring planting gives the plants all summer to establish a root system before the next winter.