Lots of history. Lots of things to do for all ages. IOP is very family friendly. Culinary scene probably doesn't matter much to you with kids but it is amazing.
Hands down you should do this. I'm a tad biased,though. If you want I can send you an email with more specifics as I'm pressed for time at the moment.
The other suggestions for Kiawah (which is amazing,too) and Seabrook are good but they're not super family friendly and there's not much to do out there outside of golf and tennis. You'll find yourself wishing you weren't so far from Charleston. We go out there from time to time to stay at the Sanctuary and "get away" if that means anything to you.
Most of my friends with kids that have come here have loved it and a few of them plan to move when the time is right.