Three blottos, 2 paper bags and a ..............

Maybe on the fith day i will get "five viable systems", even tho I
would gladly accept just one.

Man I was looking at some ozzie weather data and average July monthly
lows were 6 to 9C in areas with average July highs around 15C. So you
should be able to viably size something up there as easy as in Bermuda.

Maybe with some long underwear and passive solar you could frugally get
by without any heat. Perhaps a central fire place and burn some
kangaroo chips or those pesky rabbit droppings. It seems to get dry in
summer with some high temperatures so maybe your swamp cooler works.

Have you considered adding a mixing box to the inlet of your swamp
cooler yet, that would allow from 100% outside air to 100% return air.
I was thinking that you could switch it to 100% return air in the
heating mode, cycle the water on and off to keep humidity up, plus use
that high volume of air flow to equalize the temperatures through out
the house from the booster heat pump or central fire place.

Have you ever heated or cooled anything besides your food and your CPU?

So come on, summarize one viable system then you can throw in another
nose rubbing on me.