Beverly - I actually have a copy of The Githens Family in America. I have found a few minor errors, but it still a very good place to start. Something I have found that can be very frustrating is people going by their middle names. I had a terrible time trying to decide if one of my ancestors was Frank or Thomas Franklin. Turns out they were the same person! You're right about the last names too; I've seen Githens, Githins, Gittens, Giddens, Giffens, etc.
As for the will I mentioned, it was executed in County Surrey in England.
I have also found some very interesting entries in the Millenium File. John Githens (b. 1720 in NJ) was son of James (Christened 1700 in Barbados) who was son of John (Christened 1689? in England) who was son of another John (birth and Christening unknown). I wrote to the person who was listed as the contact for a source of the info, but no reply yet.
As for your ancestor James, I did a quick look throughancestry.com and could not find a 100% positive candidate. But I did find this marriage record:
Gittings, Henry/Smith, Rebecca/01 Mar 1797/Kentucky Bourbon County
Which then led me to this:
James Hillary Gittings b. 1769 d. unknown Father: McKenzie Gittings Marriage: 12 Nov 1825 in [city], [county], Kentucky, USA Spouse: Catherine Sansbury Born: 1770 Died: 22 Dec 1834 Children Mary Ellen GittingsF 20 Nov 1830 in [city], Washington, Kentucky, USA
Not sure if that's who you're looking for, there were a lot of James Gittingses born between 1730 and 1770. I hope I haven't confused the issue.