Skyelark is participating in her 2nd world ACR and I believe has places available for leg 4 Marquesas to Tahiti and leg 5 Tahiti to Tonga.
Links to their blogs from the 2014 WARC for these legs are belowhttp://skye51.com/worldarc2014blog7.phphttp://skye51.com/worldarc2014blog8.php
The legs are about a month each if you can swing that much time off work. I unfortunately have work commitments for the next two years that prevent me from taking more than 2 weeks at a time so I'm only sailing the last leg, Grenada to St. Lucia.
I've chartered with them many times, about 280 days on board over the last 8 years, and you won't find a more experienced or welcoming crew.
The short blogs are good reading, even if life/work commitments won't allow that long an escape from everyday life.