I agree with XXX. Find a school that's got a good a reputation for producing good instructors. I don't know any myself (unlike IFR schools with good reputations like Bini's and JAS). And from what I hear off the grape vine, CASA FOIs are getting really picky with the language you use in your briefs. Some have been known to fail the brief, simply by using non standard terms.
And it's a pity there aren't any flying schools that specialises in flight instructor training as I believe flight instructing is a specialised field, just like how aerobatics is. And IMHO spin recovery should be taught in a Flight Instructor's course, even if it's not instructed to students these days. Find a school who will teach you this.