if you have 365 version of excel
=SORT(UNIQUE(FILTER(A2:B8,B2:B8<9)),2)
sorted by value
BUT you say Unique list if LESS than 9 - BUT then say you dont want a,b,d,e,f, because they are less than 9 ? confused do you want a list that is less than 9 or more than 9
A has an entry 8 and an entry 10 - so less and more than 9
=SORT(UNIQUE(FILTER(A2:B8,B2:B8>9)),2)
still includes A as you have an entry of 10 in the list
or is it the SUM of the letters you need to consider ?