You might look into the FBCC Omnium in Asheville, although from what I understand despite the fact it's in the mountains, the RR isn't that hard. We also have the Crossroads Classic in the last week of July. I can't tell you first hand about them though, as those events conflict with RAGBRAI, my ride 500 miles, screw off, drink and eat pie week of the year.
http://www.ncsccyclingassoc.com/race...08&goToDate=Go