If you and your wife don't mind flying economy, your best bet is probably the ASEAN air pass, sold by most ASEAN airlines, for instance Thai:
http://www.thaiair.com/flying/aseanpf.htm

It is somewhat limiting in that you have to buy your ticket 'overseas', in what appears to be Europe in your case, on an ASEAN airline, which seems to exclude CX.

However it is very flexible since you get to fly point-to-point on any ASEAN airline, as opposed to the CX pass which makes one transit through HKG every time.

If you need to go to North Asia, I would use miles for that, and do Southeast Asia on an ASEAN pass. The award levels on UA and NW intra-Asia are particularly attractive IMO (20/30K) compared to the ticket prices and, as their hubs are in Narita, quite convenient for Northern Asia.

Intra-Asian award levels on Asian airlines are rather high in comparison.

There are also some good deals in the European FF programs if you do your homework, eg. 20K points for most Asian segments on KLM (i.e. NW), including potentially not inexpensive routings such as ICN-NRT-HNL, or the odd HKG-MNL flights on AF or ex-SR.

I am unaware if the ASEAN pass fares are good for miles however, as I have not yet found the time to treat myself to an extended holiday there. Enjoy your trip!