JockScot is right. (You were not supposed to let the secret out) Here in Boston, Massachusetts, U.S.A. we have two tea blending companies. The Tremont Tea Room on Winter Street (Downtown Crossing stop on the tube) and the Boston Tea Company on Rowes Warf, Boston Harbour.(Aquarium stop on the Blue Line tube) Both will custom blend small lots of teas and package as loose or in sachets for brewing. The Tremont Tea Room stocks many teas imported directly from the U.K. and Scotland, including Taylor's of Harrogate.
Where the question is of what to buy in Scotland.. I will defer to those that live in Scotland to better answer the original question.