different flight arrivals- where is a good meeting palce at SYD
 

2 of us are arriving on dl 17 and the others are arriving on QF12 later this months same departure day from lax- and same arrival day - with close arrival times. is there any easy meeting place to arrange? if they do arrive in the same wing , is there any logic to meeting at baggage claim ? or outside customs ? thanks for any advice, as i have lost folks at airports before.

You can't stay airside -- there are no facilities and you will attract attention from customs, at a minimum. After clearing customs, the international terminal is quite small and you can meet at the coffee shop directly outside the exit from customs. Really no problem finding people, it is a surprisingly small area for such a large airport. You could meet at McDonald's, for example (there is only 1 and fairly small).

The other thing you can do and what I've done in the past, there is a public waiting area just outside both arrivals halls. Depending on how long it is between flights arriving, you could easily go to one of the various cafe's landside (consider going up stairs to the departures level, much better choice) and at an appropriate time (eg 20 minutes after the DL flight arrives) you could wander down to the appropriate arrivals hall exit.

If one of you are coming on DL 17 and another on QF 12 its going to be impossible to meet before clearing customs as QF 12 will use hall A/B and DL will use hall C/D.

Once you pass customs there is a meeting point in between these two areas or an information kiosk. You could suggest those two places (although depending on your traveling companions this may just cause more problems). Alternatively, you could suggest that you meet at the entry to the Train Station which is a fair way from the C/D Arrival Hall but is a single point that is hard to miss.