Google Tampa Port authority and you will find official web site with full information and it also gives you driving directions to the port from where you will be staying pre cruise.

You are obviously using flyglobespan, and we used them one way Glasgow-Sanford for a Transatlantic from Ft. Lauderdale to Barcelona back in March this year. We hired a car, and picked it up at Sanford airport, it is so easy to do. You can do that with flyglobespan, and there will almost certainly be a drop-off close to the port in Tampa and they will shuttle you to the ship.

You can google car hire in Florida and probably get a better car deal, we did that as Flyglobespan do not provide car hire with a one-way flight! No matter who you book the car with, you will be able to pick it up at Sanford Airport.

The pricing seems fair, and presumably you know that September is in the middle of the hurricane season! Anything else, just ask.

You can also get a train from Orlando to Tampa ( there are two daily - one is actually a coach journey of two hours and skip the driving altogether after your long flight, and then taxi over to your hotel. Check with your hotel whether they provide a complimentary port shuttle, lots do, just tip the driver. If you know which hotel, it's probably stated on their website.