There are two pretty close to your vacation spot.

1. as you have said is Bass Pro. Depending on where in Miami you are it's about 20 miles or so. But it's straight up I-95 and get off at the Griffin Exit. Couldn't miss it if you wanted to. It's just a mile south of the Ft. Lauderdale/Hollywood international airport.

2. is Jet outdoors world located down in Dade county by the University of Miami and Cora Gables. They have some really great stuff but be warned some of it's a little pricey. Small store but packed with hunting/camping gear.

All the other sporting good stores around are basically just like everywhere else in the country, but slanted towards Florida water sports, and not as much hunting. Lots of fishing stuff though.

Hope it helps you.