This can be tricky. I'm not on a salt-restricted diet personally, but on occasion I've tried eating lower sodium just to see what it would be like (I don't each much sodium to begin with since I cook for myself most of the time, but I wanted to try going even lower sodium). I wasn't very pleased with the "Mrs. Dash" blends, after trying out several varieties. They all tasted "stale" to me as if I could have made a more flavorful blend myself by raiding my spice cabinet. In addition, I didn't care for the harsh flavors - many of them crank up the black pepper and acidic levels to compensate for the lack of salt, but they wind up tasting harsh and bitter.
One of my favorite things to do would be to cook with fresh mushrooms, and low sodium/salt-free crushed tomatoes. Both have chemical compounds similar to MSG (i know, i know - but they're natural), which give a "meaty" taste that helps fill in for the lack of sodium. Also, I try to play up some of the natural sweetness of ingredients, fresh basil, tomatoes, bell peppers, corn and such. Salt free butter also adds some decadence.
As for chicken stock, perhaps up the veggies, and add a little tomato paste to it for some additional depth of flavor. You could also roast the garlic before adding it to the stock.