If kept in pairs or with other cichlids then yes they will, if kept solo possibley not.
It does take alot longer for it to develop then with flowerhorns, with vieja it's all about patients.
Of course you do. Those are I think pretty old fish....like 4-6 years old or more. And they are really good specimens. I've had several Syn's, and only the most recent one has any kind of hump at all. The others had no hump at all, they were foot ball shaped, and never developed a hump after 2-3 years.
If you want fish like that, start buying some now and growing them out, and cull the ones that aren't like these in the video--it's gonna take some time.