Wow! Judging by the list of products available at that dealer you linked to I am VERY glad I don't live down under.
They seem to carry none of what IMO are the top name brands. Most of what I saw on that site I would not buy. Scary.
SEIO's are the best powerheads for a fair price. Tunze are THE best but $$$$!
Also Coralife Super skimmers, Turbofloaters, ASM, Deltec, Even Reef Octopus skimmers are all good but none listed on that site.
As for lighting, T5's are great but they HAVE to be T5HO!! Not just T5! Also have to have 8 bulbs on a tank that size to be able to keep almost anything.
Your existing heater should be fine.