I would not advise buying a house at all when you're broke.
It's one thing to have thousands of dollars saved, and then choose to get a loan with a low down payment to preserve those savings for emergencies, but if you go into a house with zero money put aside, what will you do if the furnace/AC goes out, or your roof springs a leak, or hurricane waters rush under your front door from a flooded street? (The homeowners insurance the bank will require you to get doesn't cover flood damage.)
I can almost guarantee that within six months of moving into a home you will either find something that needs to be fixed that you didn't notice on your pre-purchase tours, or something significant will break that wasn't broken when you bought the house.
If you don't have enough set aside to pay cash for those repairs, in addition to your down payment, I think it would be really unwise to buy a house right now.
That said, there are some zero-down mortgage programs.
Most of them charge fees, and your monthly mortgage payment could be $100-$200 higher because of the fees, so the same house will cost you significantly more if you don't put 20% down.
Even with the low down payment programs, I would recommend putting at least 10% down so you have some immediate equity in the house. As volatile as Miami housing prices are, you could find yourself upside down in the house, owing more than you could sell it for, if you wanted or needed to move when prices had dropped--when the bubble burst in 2007, Miami home values dropped by 15% by 2008, and another 30% by 2009.
Hope you find the house of your dreams, and that you can own it, but hope you won't let it own you.