In terms of the structure; once you've purchased a property, it's usually whoever holds the land will become the seller once you develop it.
For instance, if you buy a block of land in a company and develop it, the company will still own those blocks of land at the end of it - so really, that's your development entity. You've really got to get the right structure before you purchase the land or the site. If you do want to change it later, you've got to consider stamp duty as well. Even if you're selling it to a related entity at least in Queensland, the Office of State Revenue still takes a chunk out for stamp duty.
We have had clients where we actually change who owns the block or the site, for various reasons, but one of them may be that it could be a better tax outcome. We might want to use a company, but a trust gives us that flexibility of where the profit goes at the completion of the development.