I would probably just use freshly ground chuck from a butcher, not a supermarket where I don't know how the beef is processed. Also I NEVER buy those round tubes of fresh or frozen ground beef. Nor will I ever buy at Walmart again, looked nice but turned out to be real fine grind like pink slime.
Next I would use at least 1-1/2#. Soak some preferably French bread crumbs in milk (that makes them fork tender). Then I would probably use one egg.
For seasoning I might use something like that new can't believe it's not boullion or crush a boullion cube. Then maybe no salt but hand ground pepper.
I've got some frozen chuck I got at a different butcher and am trying to figure out what I want to do with it.
Meatballs are tedious but worth it. Shape with a certain ice cream scoop I have (medium), brown in the oven at 400 for awhile.
Then I would put the seasonsing I want in the sauce and finish the meatballs slowly cooked in the sauce.
Sounds yummy as a sandwich with some French bread.
In my sauce since I don't have home-canned tomatoes, I used whole cut up or crushed and one can sauce and one can paste, water as desired (go easy on it). Then minced garlic, quite a bit of basil and less oregano. I forget what else I put in it. Not much. The sauce simmered for 1/2 hour is good and better the next day. The basil is the key flavor.
Last year I got the meat grinder attachment for my KitchenAid stand mixer. I grind all my own meat now...takes a little time to cut and trim..but well worth it..when you know what is NOT going into your ground meat. I make a lot..then freeze them..