I don't work in the Orlando area, but my head office is there. I'm at the gulf beaches.
Many of our clients come from the UK as I and fellow realtors do.
It is most important that you do your homework on buying here. Our company website gives a lot of useful information to buyers. I'm sure other Orlando area ones do.
The people who make claims that you are 'guaranteed' 30 or more weeks per year income are giving sales talk, and you should talk to other owners. You can do this yourself by looking in places like Dalton's weekly and calling some of the advertisers. Some will tell you to get lost, others will be honest. Also look at websites , like vrbo.com (check the letting calendars to see how they are doing) and consider using this service yourself. Management companies can't do it all, you need to get your property known out there.
If you are buying a home that is already used for rentals, ask for their last 2 years tax records for sales - they have to declare rental income for sales and tourist taxes, and from that you can figure out their rental income. If they have other rentals and don't declare them (shocking I know

) then you can assume there is potential for further income. Course you have to take that info with a pinch of salt.
If you are coming on a buying mission, don't see too many properties each day, so that you can take time, away from realtor, to come back and view yourself the one or two that are most likely candidates. Get a shortlist drawn up to view when you come, by receiving information in advance of your trip and go over good and bad points, plusses and minusses that will help narrow down your search criteria beforehand and avoid you wasting both yours and the agents time.
When you come over bring enough funds to open a bank account and have enough in to write a sensible security deposit for a contract offer - say $1000. This is safely taken care of don't worry. Ask your realtor about process for a contract, it's all good when you work with an agent. Try to stick to agents who actually understand the UK market, so they know where you are coming from. There are lots of good ones I'm sure in the area.
Finally remember in Florida, excepting for contingencies written into a contract, once you have signed and the other party has agreed to your terms and signed, you are commited.