Hunter Family from Scotland to County Down

I am searching for more information on the family of EDWARD HUNTER, born 15 Oct. 1731, Daff, Innerkip (Inverkip), Renfrewshire, Scotland; chr. 17 Oct. 1731, Daff, Innerkip (Inverkip), Renfrewshire, Scotland. Edward is my 5th great-grandfather and he apparently emigrated from Scotland by way of County Down.  As far as I know, Edward was the only one of his siblings to come to the US.

Edward's parents were EDWARD HUNTER, b. c. 1696 Daff, Innerkip (Inverkip), Renfrewshire, Scotland, and ELIZABETH KER, born Dec. 1695, Innerkip (Inverkip), Renfrewshire, Scotland.  They married about 1720-1721 and had six children: Malcom, b. 30 May 1722, chr. 3 June 1722; John, b. 5 Aug. 1724, chr. 9 Aug. 1724; Anna, born and chr. 1 Jan. 1728; Edward {previously mentioned}; William, b. 10 May 1734, chr. 12 May 12734; and Robert, b. 17 March 1736, chr. 28 march 1736.  {All children's birth and baptismal dates from GRO Parish Records.}

William A. Hunter, for many years a historian with the state of Pennsylvania in the US, states that the Hunter family came from County Down before they arrived in Delaware by the year 1755.

By that time, Edward had married to SARAH [Last name Unknown] and they became the parents of their first child, JOHN HUNTER, born 2 Dec. 1755, in Mill Creek Hundred, New Castle Co., DE.

Can anyone help me find out if there is more information on Edward Hunter while he resided in County Down?  I have the feeling he may have only lived there for a short period of time.

I'd appreciate any assistance!

Thanks.

Ceiligh