I don't think you're being neurotic. Not only can you control the sugar more by adding your own fruit, but the plain also has more protein than the ones that already contain fruit.
I ordered a book from Amazon.com called "Eating Well After Weight Loss Surgery". It offers a great deal of recipes and even tells you how to prepare them depending on how many weeks out you are post op.
I'm still on pureed foods, but I have been blending "light" canned soups and adding unflavored protein powder. It tastes like the soup but I get the extra protein in. Tonight was beef & barely.