ISO: Sweet and sour meatballs

We are serving meatballs this weekend at my BFF's son's wedding reception.

I am supposed to be the slave labor. When I talked to her tonight, she is talking about making meatballs in spaghetti sauce. I thought we had decided on sweet and sour meatballs. I believe the change came when she could not find s&s sauce in a large quantity.

I think I can persuade her to sweet and sour, as long as it is not complicated. I have found the chili sauce/grape jelly recipe. How do I adapt this recipe to a slow cooker? We are using meatballs bought at sams. They say to cook in a slow cooker on high for 3 hours. How much "sauce" should I make for a crockpot full of meatballs? Has anyone else done it this way?

Thanks