Hey Pete,
its not multi-day, but theres the Mug race in early May that will give you a taste of distance racing. Its a pretty awesome race from what I'm told.
And the Reef Run (single or multi day, I think), Miami to Key largo (single day) and if you wnat to come to the Outer Banks of NC ,The Duck Cup(2 day) .
Here's a few more, scroll down to distance races.
http://www.catsailor.com/cs_schedules.html