Rehearsal dinner in Myrtle Beach
Depending on where you are staying and how far you want everyone to drive. There are restaurants down on the water in Little River, that might be fun for everyone to walk around. I don't know if there is a 'delicious' restaurant, but scenic and fun.
Joe's Bar & Grill used to be the hot spot many moons ago.
Are you renting a house? Having it catered might be fun, you can have southern bbq or a shrimp boil with big tubs of wine and beer. If you have it catered, I would make sure you hire staff so you aren't stuck cleaning.
If it's convenient, I would go to some restaurants and see who has private rooms. Parties in the middle of a normal restaurant is too loud when you are wanting to toast or just even talk! I'm a wedding photographer if you need one! lol