Thanks for the reply, Heather. That's a bit too specific and a bit late, though. I really have no idea where in the lowlands my family came from, yet. Angus is one of several counties where I found Reas living in the 1600s. As for my particular line, the earliest ancestor I know of for certain was William Rea, born in Drumskee, Dromore Parish, County Down, Northern Ireland in 1680. I have found Reas living in County Down from as early as the 1630s, and I believe these may have been William's ancestors, though I can't establish the link to them. So, any emmigration from Scotland would have occurred probably around 1630 or earlier.
Gary Rea