Sydney winter

brad16 says...
Most will 'survive' winter in Sydney. Reliably producing fruit will be an extra challenge.

Rambutan will need more artificial warmth than it's worth, over winter just to get established. On top of that, it would be almost a miracle to get fruit from it. I'd put that one in the 'find something else' basket.

Starfruit 'survives' without artificial winter warmth in COASTAL Sydney, but I haven't had any establish and fruit yet.

Custard apple will be ok, maybe baby it while still young.

Sapodilla, I've had survive Sydney winters. Fruit producing I don't know about because they were relocated north while still juvenile.

The others should all be fine. The longan will be a better producer than the lychee, and would probably be the most suitable choice of your selection. I don't have much experience with pomelo outside of having the wildlife eat the few I had to the ground.

Good luck with whatever you go with.

ps. Some parts of western Sydney can get freakishly cold in winter. I'm not familiar with the particular location you are from. I don't get frosts. If you do, revise my advice down an optimistic level or two.

I know of discussions on here about longans in Melbourne. Again, I think they would be the best ones.

Also just realised that I was talking about 'star apple' (Chrysophyllum cainito) above, not 'starfruit' (Averrhoa carambola). 'Starfruit' (Carambola) will be better suited to Sydney climate than the 'star apple' I was talking about, though the carambola I've had all died mostly of water deprivation I think. Never really cared for them enough to bother replacing them.