We have a large frangipani tree that needs to be moved due to the e tension but my concern with relocating the frangipani tree there would be the lack of sunlight. Another idea was to scrap the feature tree & replace it with a fern tree & make it lush with shade loving plants. Attached is another pic with a different design idea. Thoughts ?..

Congrats on choosing blocks for your garden bed. If you're looking for trees, I suggest considering a maple tree. They grow nicely over time, providing shade and privacy. I recently moved to a new house myself, and I'm also exploring plant options. Back in my hometown, we had a reliable tree service that helped us with planting and maintenance. Maybe you can find something similar in your area. I came across this website, https://www.deepdale-trees.co.uk , which might be helpful for you. They offer a variety of trees and services.

wow I had no idea you could do something like that! It's so nice to see the tree saved. Maples are fairly slow growing so it's nice to save it.I have baby birches dotted around the lawn and I live in fear the kids will snap them off by falling on it.

Oaks have acorns. Maples have samaras, which are small. Some self seed quite readily but that varies a lot, I don't know if that's the case with the celebration maple you have in mind. What I suggest you do is check the label in the garden centre and then go to the website of the grower for more information. It can be helpful to do a search too and see what other websites say about the plant. There are often useful details which are not included on the label. This grower has a fantastic website for trees. https://www.flemings.com.au/nurseries/# They have information on Celebration maple. It's reported to be seedless. 12m H and 9m W is large so check if that suits as there's a huge number of maples of various sizes. https://www.flemings.com.au/nurseries/acer-x-freemanii-celzam-celebration.html Do you want a deciduous tree so that valuable winter sun is not blocked, or doesn't it matter in the location you will be planting? If it doesn't matter, for example if it isn't on the north side of the house, then you might prefer to avoid the raking of autumn leaves. I love Bigreader's suggestion.