I've been looking at NZ for a while, but you need to have sufficient savings to support yourself while you job search.
In theory you might be able to find one before moving (your skills are a lot more specialist then mine) but generally speaking recruiters like to know you're in the country rather then take a risk on the immigration process.

Austrailia's minig sector is booming, but I've heard mixed reports about job reliability. Only heard mind, there's a few ozzies on the board who'd know better.

Think hard about why you want to move country? Is the new country exac tly what you want, or are you just fed up with blighty? cos being annoyed with your home country won't get you past the first three months in a new country. trust me.