I'm not sure how you can make spaghetti and meat balls with pasta sauce low sodium. All 3 bring sodium.
Dude, two words: scratch cooking. I made egg noodles this weekend--100 g flour per egg--with no added salt. Delicious. Get off your a** and make a simple, from-scratch tomato sauce using no salt added tomatoes, onion, fresh basil, and whatever else you like: again, no added salt.
Plain beef has around 60-80 mg of sodium per serving, so the meatballs deliver a little hit, but again, this dish is very easily reproduced with very low sodium. Seasonings don't add salt: onion, garlic, oregano, basil, plain bread crumbs, egg, etc. A tiny pinch of good quality grated pecorino over the final dish won't break the sodium bank if you strip the salt out of the components.
If you're avoiding salt, you must avoid packaged foods. It's pretty easy to reduce salt if you actually cook things from scratch.