Hi Natalie,
When I was on holiday, I was only able to get 3 months. As being retired and owning a house I got six months. So at airport immigration ask for 6, and if they only give you 3, an extension for 3 months will cost about $100 bbd downtown at immigration. As for starting a business, it would be best to be here and get all the info and forms that you need at immigration. If you already have a lawyer, they should be able to answer any questions related to starting a business on the phone.