When picking a contractor it is very important to go to myfloridalicense.com to make sure the c contractor you are talking has the proper license. From that same location you can also see if there are any complaints against them.
It also important that you don't let the contractor try to get a 1/3 downpayment. There could be delays and so I'd doesn't make sense to tie your money up.
And finally it is important the contractor's works have the experience and skills to do the job correctly.