My tastes with protein powder completely changed from preop to postop.
I've tried and hated EAS, Designer Whey, Muscle Milk light, Adkins, the one they have at Wal-Mart (Body Fortress), one my Nut recommended from Trader Joe's, and a couple others. Mostly they are too sweet or the texture turns me off. Others I've eliminated because they cost too much. Or they were okay when I first tried them, but I can't handle having it more than once every 2 weeks now -- lookin' at you Mango Nectar!!
So, I recommend getting samples from Vitalady.com, Chike, Unjury. Try not to buy a big bucket of something you may end up hating.
Right now the protein I like the best is Isopure Zero RTD. I'm really not too fond of 'milkshake'-like protein. But I do use the generic protein powder from Whole Foods -- I make chai tea and 'cocoa' with it. I have some unflavored Isopure powder I mix into stuff (it does funny things to baked goods).
I do buy the Premier Chocolate RTD from Costco. It's vile, but I 'chug' it down in about 10 minutes while I'm driving to work -- 30 g of protein is nothing to sneeze at. It helps me avert my eyes when I walk past the donut box on the way in. (No chugging for early postops!)
Regarding telling people, it's a personal choice. I do think because we all started out super morbidly obese that people don't give us as much crap as they do lightweights, but we do still get crap from some people.
For the most part, I don't care who at work knows. I haven't had anyone freak out on me about it. But don't go and join the "Weight Loss Challenge" at work because most people don't realize that postop you have to work for weight loss even with the surgery.
I do have a couple of people who watch what I'm eating.

One of them congratulated me when I brought a salad for lunch a couple of weeks back. She didn't see me eat the meat off of it and throw most of the greens away. But for so many people diet=salad. You can't escape it.
You do need to memorize this for dealing with concerned waitstaff at restaurants: "I guess I wasn't as hungry as I thought I was." The questions about if the food is okay get really annoying...