Hi there,
I'm sure there are plenty of good mechanics in Canberra, however if you fancy a day trip up to Mittagong, Trevor Verahey who owns Dragon Motorcycles knows the ST1100 very well having worked for Honda when they were in production. He did a major service on my ST earlier his year to establish a good baseline going forward. Cost about $1200, however I felt it was well worth it.
Andrew.