I would suggest trying the Marriott next door to Disney's Beach house. It used to be a Hyatt and they had one there. There is a Westin Resort at one of the other plantations. I would guess the large hotel resorts would be your best bet.
Connears
From what I hear the Westin has a fabulous but expensive Brunch. Also consider Cafe Europa in Sea Pines, not a Buffet I don't think but good never the less.