Why don't you make your own salad dressings. Most of the WW related web sites have recipes. Try making 1/2 the recipe or 1/3 to see if you like it. Most recipes sites have a search, give that a try. What kind of dressing do you like? Put that into your search. Try some of the clone web sites
www.copykat.com, topsecretrecipes.com and search for dressings. salad dressing or even salads. You can always take a high fat recipe and cut it down with f/f or low fat ingredients, like mayonnaise. With vinegars, mustards and spices in the recipe you won't know it has f/f mayo.