This would probably depend on your tolerance for risk taking. It may be perfectly fine to purchase but personally, I would not buy a diamond online that I could not return after I viewed it personally and I found it to be unsatisfactory for my tastes. This is a call only you can make.
So we bit the bullet today on the stone Kim N found - 1.4ct D, VS2, ideal round. Decided to take the risk. I plugged it into the HCA tool and was happy with this result:
Funnily my partner offered for me to go bigger/spend more but I just couldn’t justify it. We have four young children, are building a new home and now will have a wedding to pay for too. This size stone is already bigger than anything I ever thought I’d get now that lab grown an exist; so I’m over the moon. A similar specced earth grown stone would cost over $20k AUD, so this is basically a 10th of the price.
Thanks for all your help, will update when I have CADs and of course the actual ring!