I have know idea what brand your using, but a good quality Lift-n-Slide door system should have a pretty shallow sill that would dam near be floor height. Even for the Impact requirements.

Our house is over 4 miles inland in Boca Raton, but, I am inclined to try to comply with the "Miami-Dade" requirement (which I believe are more stringent)so that our windows will be in compliance with any future changes in building code. Our insurance company is telling us that they want our doors and windows to meet current building code requirements (for wind). Are there different dp ratings required for different areas in Miami/Dade? Eo you know what dp rating is required for Boca Raton? Thank you both for your help.

Looking at Florida's wind speed map, it appears that you are in the 140 mph wind zone. This would equate to a DP50 requirement in your area.

You would be well suited to see what minimum code is and far exceed that. Miami Dade code is pretty comprehensive in this case because of that regions affinity for disastrous storms.

I would not install a DP50 door alone unless you plan on have hurricane shutters installed afterwards.

While hurricane shutters are nice, the beauty of Impact windows/doors is that you are not relying on the shutters alone. Most people opt for impact windows/doors on vacation properties because they do not need to be there to close them as them would a shutter.

The combination of both would give you ultimate impact protection.

The Simonton Stormbreaker line is a nice option although I am not sure of their availability in doors.