The key to making meatballs that aren't dense is to mix a liquid with the breadcrumbs before adding the meat. The breadcrumbs will hydrate and create a lighter meatball. Most Italian meatballs contain Parmesan cheese or milk. They don't contain dairy, but you won't be short of milk or cheese.
Even if it's not dairy-free, this baked meatball recipe is great because it's easy and doesn't require bread from the day before. They taste like real Italian meatballs to me, but it's been a while since I ate a meatball with cheese.