A few notes:
AAdvantage members can upgrade full-fare tickets on AA stock. You need to be flying at least H to earn AAdvantage miles. If so, sign up for the Gold Challenge (details at
www.fewmiles.net) to get your elite status (or the Platinum Challenge if you think you can complete it)
AsiaMiles offers one-way and round trip upgrades from discount fares.
If you're stuck in coach, you might be interested in this thread:
Coach service on CX, how is it ?
http://www.flyertalk.com/forum/Forum85/HTML/000614.html
Good luck!