Matt,
Not sure what you have and what you don’t have. Family in 1911:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Ahoghill/Carmacmoin/115138/
That farm in 1901:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Ahoghill/Cormacmoin/923917/
Samuel Bankhead in 1901:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Ahoghill/Lismurnagha/924087/
There’s a bit of a jump in Samuel’s age between the 1901 and the 1911 census, but they ewer never too accurate with age sin those days. Judging by the GRONI indexes his correct date of birth was 28.8.1875. So 26 when he married and 36 in 1911 seems OK.
Probate abstracts from the PRONI wills site which mention Bankheads from Lismurnaghan:
Bankhead, Andrew of Lismurnaghan Ahoghill county Antrim farmer died 1 November 1933 Administration W/A Belfast 5 November to Thomas Bankhead farmer. Effects £343.
The Will of James Bankhead late of Killane County Antrim Farmer deceased who died 17 December 1874 at same place was proved at Belfast by the oaths of John Bankhead of Lismurnaghan and Cuddie Bankhead of Killane both in (Ahoghill) same County Farmers the Executors.
The Will of John Bankhead late of Ballybollen County Antrim Farmer who died 16 November 1885 at same place was proved at Belfast by James Bankhead of Ballybollen Grocer and John Bankhead of Lismurnaghan in said County Farmers the Executors.
Bankhead John of Lismurnaghan Ahoghill county Antrim farmer died 18 December 1942 Probate Belfast 2 March to Robert Logan Bankhead and David Perry farmers. Effects £676 10s.
The Will of Robert Bankhead late of Lismurnaghan County Antrim Farmer deceased who died 10 December 1874 at same place was proved at Belfast by the oath of John Carson Bankhead of Lismurnaghan (Ahoghill) Farmer the sole Executor.
Bankhead, Robert Logan of Lismurnaghan Ahoghill county Antrim retired farmer died 6 October 1963 at Braid Valley Hospital Ballymena county Antrim Probate Belfast 25 March to William David Perry farmer. Effects £6596 16s.
The Will of Samuel Bankhead late of Ballybollin County Antrim Farmer deceased who died 17 October 1872 at same place was proved at Belfast by the oaths of John Bankhead of Ballybollin and John Bankhead of Lismurnaghan both in (Ahoghill) said County Farmers the Executors.
Several of those wills are on-line on the PRONI wills website. For the others you would need to get a copy from PRONI as they are still in paper format.
1st Ahoghill graveyard:
Erected by Andr. Bankhead, Lismurnaghan in memory of his father Robert Bankhead who departed this life 10th Decr 1874 aged 69 years Also his mother Jane Bankhead depd this life Feby. 1883 aged 70 years Also his children Jane depd this life 12th July 1901 aged 25 years and Sarah Ann Depd this life 20th June 1892 aged 22 years
Erected by John C Bankhead of Lismurnaghan in memory of his father Alexander Bankhead who died 4th Augt 1871 aged 60 years
There are other Bankheads on the Braid site:
http://thebraid.com/genealogy.aspx
Griffiths has Alexander, William and Robert Bankhead in Lismurnaghan in 1862. You can follow their tenancies through using the revaluation records, to see when they changed hands.
https://www.nidirect.gov.uk/proni
Tithe applotment records for Ahoghill list a Robert Bonkead in Lisnafillon in 1825. He’s the only farming household shown in the parish.
http://www.irishgenealogyhub.com/antrim/tithe-applotments/ahoghill-parish.php#.VxCbQqt9eg0
The 1766 religious census of Ahoghill parish lists a James Bankhead.
http://www.ulsterancestry.com/ShowFreePage.php?id=328
PRONI has Lismurnaghan National School records in SCH/1155. You might find the Bankhead children’s attendance records etc there.