I've ruled out Richard Buckland (1750-1829) and Mary nee Harvey as being the parents of the children born in Hitcham, as they had children in Stoke Poges up until 1787, which is 7 years after the first child was born in Hitcham in 1780.
My guess that Richard was born 1750-1760 is based on the date that the first child was born in 1780. I've guessed that he would have married between the age of 20 and 30.
In the Bucks FHS baptisms database, there are 3 Richard Bucklands born vaguely within the right period in Bucks.
Richard Buckland born 1765 in Amersham, base son of Hannah Buckland. This Richard I believe died in 1851 at Preston Bisset aged 86. In the 1851 census he is living with his grandson James (born 1808), and his wife and child.
I guess he was too young to have a child in 1780, so he can also be ruled out.
Richard Buckland born 1736 in Langley Marish, son of John and Ann Buckland
I can find nothing on him.
Richard Buckland born 1745 in Burnham, son of Richard and Mary Buckland
I can find nothing on him.
On the burial database there is a Richard Buckland who died in 1799 at Stoke Poges. He may have been the son of Richard (1750-1829)
There is another Richard Buckland of Taplow Common, who died in 1840 at Farnham Royal aged 103, which means he was born in 1737, perhaps at Langley Marish.
There is no marriage on the database for Richard Bucklin and Mary.
In the Posse Comitatus of 1798 there is a Richard listed in Hitcham as an infirm labourer. I suppose this is the Richard I'm trying to trace. There is also a James, presumably his son (born 1782).
As you suggest, I'll start looking at Berkshire.
Regards
Skull