You may also try ... in your same neighborhood, IF you can tell who's roof is new ... go and say "hello!" Ask them about the roof and their experience with the company they chose.
If nothing else, going with someone that YOU feel comfortable with is important. And keep in mind, the roof is perhaps the most important thing protecting the house... the "cheapest" is not usually the best. (is it ever!?) haha Don't read too much into that. There is very fair pricing out there. Just don't go for the slick salesmen that try to be pushy and think that they are the greatest.
Hope you find or found a good one in your area! (we are in Dallas, TX)
1. Search Florida Department of Business and Professional Regulation
License Category: Construction Industry
License Type: Certified Roofing Contractor
web address: https://www.myfloridalicense.com/wl11.asp
2. Try Angies List - http://www.angieslist.com
Angie's List is a word of mouth network, helping more than 1 million members find the best contractors in their area. Read detailed reviews from members near you to find out which contractors to trust, and which to avoid.