http://www.flyertalk.com/forum/delta...ns-thread.html

above link contains all the current Delta promos, including the the 25,000 bonus miles + double qualifying miles for EU travel out of PHL. Wasn't sure if you both needed to score 16,000 miles but if so, above might be a little easier & less painful than the SYD run.

In regard to managing miles & earning most bang for your status & buck, again Delta forum should be a big help in that direction too.