Thanks so much, Roger, I was aware of the Rea Family DNA Project website--which is horribly out of date and unfortunately doesn't even list some of the various Scottish and Irish participants (or the Wilson descendants) on the Lineages Tested webpage! It was helpful to see how the participants you mentioned fall out. I sent a message to the website administrator, asking if he was planning on updating the website to make it more useful (for instance, noting EVERY participant's number with the lineage they confirm membership to and the geography represented by that lineage, as other Family DNA Project websites do).
Results so far indicate that the Rea surname is very heterogeneous, although UK-centered. But, it's also nice to know that I do have roots in SOMEBODY'S lineage. :>)