I work offshore so really I could live anywhere.
All the more reason to get out of London. You're not on footballers salary, but you are on above average working men's pay, so find a nice place where both you and the missus would be happy - one with potential for her cafe to start up and better schooling for your future to have kids.
Why forced to pay more than required and when you have kids, it's either send them to private school or risk sending him/her to a city comprehensive. (Nothing against them but at the rate Mr Gove is going, it'll end up worst rather than better.)
If you want to plan ahead, look beyond just what you money can buy now. Look beyond just an extra room for your expanding family.