Probably a better guide and probably not too dissimilar to that of AFC regulations (which is what I'm assuming A-League clubs have to abide by). Most NSW  grounds currently would fail a lot of those guidelines without some serious investment in their stadia. 

I honestly think the most Sydney-based A2 clubs would end up playing out of Bankwest Stadium in the end. Being located in the center of Sydney, it's not too far from the home bases of most of the NPL clubs and meets all the aforementioned EFL and AFC requirements.