When does H class availability open up?
 

I would like to book one-way CGK - HKG - MEL on specific flights in order to be on the same flights as my wife and daughter in May '08 (already reserved / holding OW AAward tix for them on the route). (Will do an open-jaw return from SYD - PER - CGK on QF a week later - if thats relevant). Currently, CX is only showing full-fare Y availability.

Any idea when CX is likely to open up H class fares for CGK - HKG - MEL for next May?

Would I be better off just trying to get the whole itin on QF when I call AA to finalize the booking? (I can already get discounted - but still AA EQM-earning - tix on QF for the dates)

That's because you're trying to book a one-way. There are no discounted one-way fares, so full fare Y always show up.

Even when I try to book as roundtrip, only part of the itinerary is available as K fare.

7 May CX776 CGK 15:05 HKG 21:00 0 18:45 343 eTicket Economy (Y)
7 May CX105 HKG 23:35 MEL 12:50+1 1 333 eTicket Restricted Economy (K)
15 May CX134 MEL 07:40 HKG 15:05 0 15:05 333 eTicket Restricted Economy (K)
15 May CX719 HKG 16:00 CGK 19:45 0 330 eTicket Economy (Y)

NB: this whole OW business is beginning to really suck for international paid travel - have to spend a fortune just to be able to earn ANY eqms.