Savage is probably the toughest truck, but the Revo is so smooth and easy to drive, and has the most room to grow with of all these trucks. When you say your wife wants to really bash, how hard do you think she is really going to bash it? If it is more likely sandlot bashing, the Revo should be able to take it, easily.
I don't know if you have seen the video of the guy who takes a brand new Revo out to a cement skate park and just flails the thing (the guy was an idiot or at the least stoned), but it is a good testimony as to how much abuse the Revo can take.