Try Scotland's People. All the dates (births, marriages, deaths) belong to the Statutory registers, which are quite easy to find (much easier than the old parish ones).
I did try the 1881 census for your family and they are there in Gairloch. Only Murdoch doesnt't appear in the household. William's age is given as 17, so probably he was born in 1864 (in between Murdoch and Isabella). If you want to take a look search for Murdina McLean (not MacLean), age 12, Census place Gairloch.
You could then take a look at the 1891 census and anyone that doesn't appear would be liable to a marriage or death search within that 10-year period.
Those Gairloch registers are usually without the "a" (McLean), but not always, so if a first search doesn't give results try again with the "a" (MacLean).
Best luck and keep posting to see if some day we do coincide with some Maclean that links our families.