Help with VA airmiles

Hi there
Im planning a trip from Melbourne to London late June/early July 2013 for 3 weeks.
I have 171,000 VA airmiles and my wife 96,000, all expiring soon so I want to use them up.
I cannot find any SYD-LHR reward seat availability for love nor money! Do they get released nearer the travel date? I want to book it all and lock in dates early, I don't want to leave it to the last minute.
I was also thinking about upgrades or companion flight possibilities. 18th June to 9th July MEL-LHR return in VA Premium Economy is just shy of A$4,000 - would this be applicable for a companion flight or would it need to be a different fare?
Would it be better to perhaps buy 2x full price Economy tickets and use miles to upgrade to Premium (or Upper)?
What am I likely to find the best availability with?
What would you do in this case?
Thanks in advance for any suggestions - going to and fro with the website is irritating me. Booking Reward flights ex-UK to the USA gives a nice table of availability so I can immediately see my options. No such luck for Australia!
Thanks
Im planning a trip from Melbourne to London late June/early July 2013 for 3 weeks.
I have 171,000 VA airmiles and my wife 96,000, all expiring soon so I want to use them up.
I cannot find any SYD-LHR reward seat availability for love nor money! Do they get released nearer the travel date? I want to book it all and lock in dates early, I don't want to leave it to the last minute.
I was also thinking about upgrades or companion flight possibilities. 18th June to 9th July MEL-LHR return in VA Premium Economy is just shy of A$4,000 - would this be applicable for a companion flight or would it need to be a different fare?
Would it be better to perhaps buy 2x full price Economy tickets and use miles to upgrade to Premium (or Upper)?
What am I likely to find the best availability with?
What would you do in this case?
Thanks in advance for any suggestions - going to and fro with the website is irritating me. Booking Reward flights ex-UK to the USA gives a nice table of availability so I can immediately see my options. No such luck for Australia!
Thanks