You may want to pick up Real Estate magazines in your area and look for ads for homes in parks that have leased land, or better yet drive through some of the parks that charge lot rent and see which Real Estate offices have signs on those properties.
Some parks have rules against signs for sale, if you don't see any signs you may need to stop in the park office to inquire. Some park offices are very helpful and may have a list of agents to give you, others are very territorial and want all park sales to go through their office and will not give you information.
The fact it is in a 55 and older community has nothing to do with who can sell your home. You should have copies of your Park's regulations and if it has a Homeowner's Association all of those documents will be needed.
H & M Realty of Polk County
A Realtor can not sell your manufactured home on leased land in the state of Florida. In order to be considered real estate the land must convey with the home. Since manufactured homes are titled like cars it takes a different sort of license to sell just the home - something similar to a car dealers license.
If you don't want to handle the sale yourself, talk to your park manager and your neighbors to see if they can recommend someone with the appropriate license.
The best of luck to you!
You need a REaltor that understands land leases and expectations of buyers looking for such properties.
Coincidentally I have a top Realtor in your area that I can recommend. I still suggest that you interview him, but he would be a good fit for your situation.
You can call me at 1-888-284-2056 or contact me via my profile.