It's really close. They're close enough to each other in proximity that you don't technically need to pick, depending on how much you want to drive or if you can get some folks to come your way. So this is a non-answer in a way but you're not going to pick wrong in either case, and may not need to choose at all.

Many Orlando providers will gladly drive out to Tampa and plenty of Tampa providers will gladly come to Orlando. Just be sure to ask if they have a minimum date length if you're asking them to visit a city that isn't their home base.  Either way, you have plenty of wonderful options in both places.  Just don't wait to book!