I'm making the same trip next month; Orlando to Biloxi and will be staying at Beau Rivage. This is the place to stay on the coast if you want a luxury Las Vegas style hotel. There is little air service to Biloxi/Gulfport. I always fly to New Orleans and drive to Biloxi. You can make it in a couple of hours. A car is definitely required unless you are only going to play at your host hotel. Watch the fees, taxes, and surcharges on the cars at New Orleans airport; they can be astounding and may double the cost of your rental.