Hi
If you type in 'Benar' or 'Benor' in the IGI familysearch.org site, you will see that there are several variations on the name, Benner seeming to be the most prevalent. Spellings of surnames could vary considerably in the 19th century; my own Bailey name I have seen as Bealy, for instance, in an index transcribed from church registers. So keep an open mind, the 'right' surname could be one of several, depending on circumstances.
Not so many Benners in Ireland though as appear in England; when I first saw the names you mentioned, Ferrie and Benor, I thought how French they sounded.
Still , a trawl through the IGI is always interesting, for the spelling variations you can get if nothing else.
Cheers,
Mags