Protein powders?
Somewhere on this site, there is a page FULL of product reviews of all types (from post-ops). You'll have to dig around for it, though, because I've only been fortunate enough to find it twice.
Carb Solutions vanilla starts out okay (kinda like cookie dough), but starts to get "skunky" after a while. Optimum Nutrition 100% Whey chocolate (GNC) is like watered-down chocolate milk...not TOO bad.
Check out products at bariatriceating.com. There are some great ideas, but if you plan to order online you may want to try advantagesuppliments.com for better price options.
I just placed my order for some products, my surgery date is 7/28/04. If you like I would be happy to let you know how they work for me.
Good luck on your surgery.