It would depend on how many people you are making coffee for as to whether this unit is to large. If you are making one or two then I would say you are over gunned - but then again if that type of unit is what you want and you only want to make one coffee a day welcome to this very appropriate website. ::) It was made for you.
The heat from coffee machines (unless you are in a very small flat) would not change the temperature noticeably in Cairns - just turn up the air conditioner. ;)
I cant help you with the rest as I have never used the equipment you mentioned.
Have you much experience with Espresso Machines??