Very good idea to restrict your betting on certain areas and I think in Australia, your 3 secluded areas would be the best options.
I also heard that Hong Kong only has about 2-3 meetings per week with a horse pool of around 700.

I think the results would be more predictable and consistant, but remember, it is the same for all punters. There would be more money to make in Melb, Syd etc if you are any good (who is??) but for more consistant winners, perhaps paying less on the tote, seclusion is the way to go...

As far as sourcing tapes and other info, I can't help you.