In a 2 1/2- to 3-inch-deep 12-inch frying pan or 5- to 6-quart pan, bring about 1 inch of water to a boil over high heat.
Cut out and discard cabbage core. Carefully separate leaves from head, keeping them whole.
Add cabbage to pan, cover, and cook until leaves are wilted, 3 to 4 minutes. Drain water from pan and fill with cold water. Drain again.
Cut thickest parts of tough stems from the 8 largest leaves; set leaves aside. Finely chop stems and remaining leaves.
In pan, mix chopped cabbage with sauerkraut and paprika; spread flat.
In a bowl, mix salmon, onion, egg white, rice, parsley, bread crumbs, and 3 tablespoons water.
Mound 1/8 of the salmon mixture at stem end of cupped side of each reserved cabbage leaf. Form the meat into a horizontal log 2 1/2 to 3 inches long, fold leaf sides over salmon, then roll from stem end to enclose. Set rolls, seams down, on sauerkraut mixture in pan.
Mix tomato juice and broth. Pour over cabbage rolls. Cover pan and bring to a boil over high heat. Reduce heat to medium-low and simmer until salmon is opaque but still moist-looking in center of thickest part (cut to test), about 8 minutes.
Spoon stuffed cabbage rolls and sauerkraut mixture into shallow rimmed bowls. Add sour cream, salt, and pepper to taste.