@Chris - sounds like a fascinating novel and Benezet is of course very well known. I now recall you had mentioned something about the book to me some months back. I'd also look into the writings of Samuel Janney (I adopted his profile but unfortunately forgot to go back and rework it but did add most of his writings) if you have not as he was in the forefront of the issue (and also of native American issues).
Some people read far too much into my asking why you asked the question.
A lot of the people you are looking for would be found in and around Philadelphia meetings who had obtained significant 'status' and there was considerable tension over displays of wealth (which by today's standards were probably tame). I would look at the journal of John Woolman (off hand I don't recall how detailed he got on this but it was a serious concern) and perhaps Janet Whitney's biography of him.
@K Smith - "Slave owning Quakers does not fit neatly into any narrative presented in todays version of the past." The statement is not supported by facts and the subject is often the topic of or addressed in research published by the Friends Historical Association (publishes Quaker History, among others) as well as in any number of books written by Quakers (Jay Worrall's The Friendly Virginians is a place to start). "My initial assumption is prominent Quakers attained their wealth, the same as most prominent men of the day did, at the expense of slave labor." Once you delve into the topic, you will find your initial assumption needs revision. Equating prominence with wealth or vice versa in the Society of Friends runs against the grain of the Friends.