routes to southeast: when and where?

[yogananda]

Hi All,
at job my boss is going to let me go for my gap year, and my dream is to get an ocean passage in a sailingboat but I don't know what would be the best time in the year for my route.
So I'd like, if I could find one or more vessels, a passage from Darwin to Southeast Asia especially Philippines and Thailand/Singapore or even better from Papeete to Philippines/Thailand/Singapore.
I could only have a pair of months to plan the project (departure around june 2012 to june 2013) but maybe wheater conditions in the 2 routes I've chosen are not so nice in that time so I need to change the area and start my trip from another place, or even in another time of the year.
While I don't have any problem to move to any city for joining any crew, at job, I don't know what range of negotiation I could have in order to push later my departure.
I will be extremely grateful to anyone who can suggest me which routes and times I should choose and any further indication will be warmly welcome.
Thanks in helping my dream.