Leveling/lift and wheel spacer recommendations

Hello, new member here. I have a 2016 Toyota Tundra Crew Cab 1794 edition 2wd. It has stock 20 inch rims with 275-55R20 tires. I have a 3 inch front/2inch back lift/leveling kit that I have not installed. Looking for recommendations on the leveling kit. Do 3 inch level alone? Front and rear? Also thinking about putting 305-50r20 tires on stock rims. They appear to be almost identical in circumference and about 1.2" wider. I am supposing I would need 1.25" or 1.5" wheel spacers. Any recommendations on the best combo of leveling and wheel spacers for these tires to work best? FYI, I am looking for the tire to stick out past the fender a little bit(just a visual preference of mine).