Traveling from mass to orlando, where to find the cheapest prices?

looking to go from 3-5/3-11-09, want to fly out of providence, where can I find the cheapest prices, their are so many places to look, orbits,expedia,aaa, travel agent, my god , any advise, will be traveling with my wife and 2 kids, want to hit 2 parks, and have a couple relaxing days

http://www.kayak.com/s/flights.jsp?searchid=BRPmGV&completed=true