Hi,
I have owned both. You might also consider the Geo-Chevy Tracker, which differs from the Sidekick in markings and trim only.
If you are planning on using the vehicle as a second car, there are some practical matters to consider.
The Samurai is smaller and more tightly sprung. It has a harder ride mostly because it has solid axles and leaf springs on all four corners. The Sidekick/Tracker has independent front suspension and coil springs all around. It has a much more civilized ride, and for light wheeling, is a very capable and reliable vehicle.
My stock Samurai would get 25MPG with its carbureted 1.3 engine. My stock '96 Tracker with the 16 valve 1.6 engine with 5 spd trans gets 28 to 30MPG IF you ignore the "factory recommended" tire pressure (23 psi) and keep them pumped up to about 32. I hear the automatic and the older 8 valve engine gets in the low 20's.
I am running slightly oversize tires (225 75x15 stock is 205) with no lift and no cutting of the fenders. I understand that 235's will fit with some rubbing at full lock on the steering. The tires do not seem to affect handling or mileage very much at all.
With both vehicles, unless you get a hardtop, you can't lock it up. The soft top offers no security.
From your description of your use and intentions, I would recommend a '96 to 98 Tracker or Sidekick 1.6 16V, 5 spd, 2dr convertible with an aftermarket hard top and 235 tires with an agressive tread. It will do what you describe and much more. And, for Florida, it's also readily available with air conditioning, which I have not seen on very many Samurai.
Good luck.