Hi! As I understand it, the set rate for a taxi from the airport to the port of Tampa is $22. I'm looking in the Tampa phone book and see lots and lots of limo services, but am familiar with none. I do see one called the Airport Connection, and you might try it. It's 727-572-1111. I have no idea if these folks are good or bad, or if they offer what you're looking for, but it's a starting point. Good luck, and welcome to Tampa.
You're going to love your cruise, whether it's aboard the Legend, or the Inspiration. Both OUTSTANDING cruises!