Here's the link to the front page of one of my favorite low sodium sites. Guy had a heart attack at 33 or so, and set up a site for low sodium stuff.
You can now buy alot of this in your supermarket, you just gotta look around. I eat sodium free, or extremely low sodium, ketchup, bbq sauces, spices, chicken broths, tomato sauce, rice mixes, and a big one is sodium free canned veggies and beans.
there has been a ton of advancement on the local grocer level on this stuff in the past 2 years as we start to all look at eating healthy.
What I do, is go to a site like this, then try a bunch of stuff. If I like it, I seek it out at the local grocer level, or I go to the manufacturer and try and get it by the case.
Be careful Jorge on salt substitutes. The potassium they are replacing the sodium with can be worse the the NaCl its replacing. Especially for me, cuz it affects the kidneys.
Hope everything works out for your father Jorge.
Site has some great info on there as well.
PM me if you got questions, cuz I've done a ton of research I can shoot your way.
Good luck brother.