I don't use protein bars (too sweet and If it looks like a candy bar and it quacks like a candy bar - it's a candy bar and I could so easily undo all the good that this surgery brought me if I had those things in the house). But a lot of my WLS friends use the Atkins bars.
Vitacost has a good range although you might be able to get them cheaper elsewhere.
Day Break® Crisp Bar Peanut Butter Fudge Crisp, 14g carbs.
Day Break® Cranberry Almond Bar, 16g carbs.
Day Break® Cinnamon Bun Bar, 18g carbs.
Sweet & Salty Almond Crunch, 15g carbs.
Plenty of others to choose from:
atkins bars - Vitacost
Vitalady's protein bars get rave reviews too -
Vitalady.com - Protein Supplements, Vitamins & Minerals and Safe Snacks!
I did try the SmartForme Proti Wafers - Proti Squares - Bari-15 once.
Melting Mama reviewed them and she gave them a big thumbs up (200-210 cals per 2 wafers, 13g carbs, 5-6g sugars, 15g protein:
Proti Wafers - Proti Squares - Bari-15 Like a sugar wafer, only better!
Available at:
https://www.smartforme.net/store/car...ct_detail&p=21
I bought a box of each flavour and there wasn't one I wouldn't recommend.
However - I managed to eat 3 whole packets within half an hour and I would probably have gone back for more if DH hadn't jumped in with an "intervention"

. They are absolutely gorgeous but they are not for me.