Hi corinne, can't help on the DNA front although am pretty sure quite a few of the Sutton Curtises headed east towards London and were still there c.1900.
regarding "Reginald Cortys, a freeman, living in 1274", were the Sutton Curtises related to the Curtis family living on the Gloucs/Berks/Oxon border? I think they had a Reginald Curtis c.1400 who was a wool exporter and had many ships and helped transport the army that went to Agincourt?