Protein wise:
Like many here love Philip Kingsley Elasticizer extreme mask. Pre shampoo per directions.
Aveda damage remedy intensive restructuring treatment mask - supposedly plant based protein. But I've used it and rec. to two clients and they like it as well.
Haven't used Joico K-pak in maybe 10 years. Not a fan since it's so readily available here, but with all of the raves, may have to revisit. I like using and rec. products to clients that they can't find everywhere and actually work well. Although I love and swear by Joico creme lightener.
For a non breakage conditioner - not a mask, but conditioner- totally swear by Davines Mellow Anti Breakage Lustrous Conditioner