2 x 240 HLG would cover that space Gazza. I'm not suggesting led produces better buds than HPS. But assuming bud quality is the same as HPS, it is cheaper in the long run,, when you factor in replacement globes for HPS and electricity costs. The upfront investment is just one cost, Your other consideration is heat, and depending where your tent is located and seasonal temps, that also needs to be factored in. I grew with HPS over thirty years ago, and I couldn't manage the heat in my environment back then( it's warm to hot here 9 months of the year). In a colder environment in Victoria, HPS may be more suitable for most of the year. Also depends if you're growing year round. Australia is a big country with big temperature fluctuations from north to south, so a QLD solution might not suit a VIC climate.