Basically most aftermarket bars you are going to find in Australia are not great quality, and always require some stuffing around.
Most panel beaters despise the products produced by these fibreglass shops, as they have to spend much more time sanding it back, adjusting, and removing imperfections than a quality factory product. Basically it takes them more time = more money, which is understandable. So they prefer the factory stuff, that "as is" comes pretty much ready to paint and fit.
The japanese original plastic or fibreglass kits are generally so much better and similar to factory quality, but then again why you're paying $500 for a copy instead of $1200+ for a front bar, etc.
To be honest, if you go for an aftermarket bar and have your car lowered (even just to the legal height) within 12 months you would have put a decent sized crack or scrape in it. Its inevitable if you drive your car, and even more so if you drive it hard. So often the stock bar isn't such a bad idea...