Hi Scott!
Good choice with Japan! If you like the serenity, rice fields, temples and shrines, then Japan is a great place to come. Before I came to Japan I thought it was full of concrete jungles.
If you need more nature around you, then I suggest teaching in Kobe or Hokkaido. Hokkaido gets a little cold at times but schools up there are desperate for English teachers.
http://www.aacircle.com.au/forums/te...-hokkaido.html
45 is not that old yet. Sure, schools will like you to be younger, so I suggest applying from within Japan. You also have a Uni degree which is great. You may also want to consider a quick TEFL course to make you a bit more attractive. When you apply for jobs, tell the schools you are available within 3 weeks notice. Would you be able to pack-up and make the move by then? This would surely impress schools too.
Let me know if you have more questions.