Hello Mike (and the Rabble!)
Welcome to Poms in Oz.
First, I am really sorry that nobody has responded to your post until now. Bteween us all, we do try to make sure that every newbie at least gets an answer and a but of encouragement.
Second, although I have no idea how to help you myself, I hope that by bumping this thread back up to the top we can get you some help.
I think it is impossible for anyone to comment on areas without knowing what sort of business you might have in mind?
I think the visa element of your plan is likely to be very complex indeed. It may be more straightforward if yours is a "household name" business in the UK, but I do not know.
With respect, my guess would be that any business plan would need to be considered in the light of and/or in conjunction with possible visa strategies for the four main protagonists in the plan. YOu might have to structure parts of the business plan to suit the potential visas rather than the other way around.
Do you already have a Registered Migration Agent on board who is absolutely competent to help with all the different elements involved in this? If not, may I sugegst Alan Collett of Go Matilda.
The reason why I would suggest Alan over & above anyone else is because in addition to being a very experienced and reputable Registered Migration Agent, he is also a Chartered Accountant in both jurisdictions. Additionally, he has set up and is running his own businesses both in Australia and in the UK. He is the man I would go to if I were in your position, my friend. His websites are here:
Go Matilda - Your Gateway to Australia - Contact and Feedback
Collett & Co
Alan is based in their Melbourne office. He can be contacted by phone or by e-mail on alan-at-go-matilda.com
Best wishes
Gill