Re:Wonders and Heroes (variant)
I've thought about something like this and it would certainly mix things up a little from game to game. Another similar idea would be to randomly remove some number of wonders and heroes from the deck before the game.
However, I would not be surprised if certain mixes of wonders could be created that would favor some civilizations over others. For example, Egypt and Babylon are typically more defensive than Rome, Carthage, and Greece. If all of the defensive wonders were unavailable, I wonder if it might tilt the scales unfairly against Egypt and Babylon.