? much help will 3/4 ton make for ride quality comp to 1/2?

It all depends on what you feel comfortable with. You could spend a couple grand putting load range E tires and suspension mods on your current truck and end up with a rig that tows fine but rides terrible when empty or you could get a 3/4 ton and enjoy driving empty or full. Since you are very close to your limit with this truck it seems prudent to upgrade to one with more capacity. Longer wheelbase and stiffer tires will go a long way to adding stability.