We're having it at Sunset Hills Vineyard, they're located in Purcellville. Check out Hillsborough and Tarara they are both really popular. A lot of people like Breaux but I found them snobby and way over priced! One piece of advice make sure you like the wine at whichever winery you choose. Since you can't serve liquor at most (or is that any?) wineries you want to make sure you give your guests something they can actually stomach. Let me know if you have any other questions I also hang out on the DC board.