As a professor, you're probably in a pretty good position to start a family. As a professor, you're probably going to have to give the university a big cut of whatever benefit you generate, but at the same time, you probably have more freedom and autonomy than most. Plus, you have a steady salary. On the down side, I don't know how hard you're working to get tenure - maybe too hard to launch a meaningful effort at a startup.

I read that at Stanford, it's pretty common for a CS professor to have started a company, almost a rite of passage. So maybe this would work out for you...