I can't imagine it being cost effective to pay someone to do this repair. Shops around here are $100 an hour and up. And this job will likely take two workers, not one, so double it.
I would start with any local marine shops. Someone proficient in repairing
fiberglass boats should be able to handle the trailer.
Best thread I have found on
Burro floor replacement. I can see a professional charging somewhere in the $5,000 to $10,000 range. Its one reason so many of these repairs are do it yourself.
https://www.fiberglassrv.com/forums/...d-55625-3.html
Project trailers are best suited for someone with the TIME, tools, aptitude, covered work area to undertake such involved projects.