There are actually quite a few barns in the wellington area, however many are large, due to WEF and the operations they carry. With that said, I do have a few friends at Team Rakowski, which is a small but very well run group out of Wellington, and then they summer in KY, MI and Chicago. Ivan Rakowski works with Margie Engle, and Jacob Pope trains many of the other riders there. I believer there is a total of 6 clients right now, so again small farm. With them being small they aren’t necessarily cheap, so you pay more for the individual attention, but they are GREAT.
If you are just looking for a good barn, there is Castlewood (as the poster above mentioned) and they have great trainers as well. In addition there is Carriage Hill Farm which is in the area too. These of course are larger operations but still really good. Ashland is probably one of the biggest in the area, but produce great horses and riders.
I would encourage you to visit a few of these placed to decide what you are looking for, and then make your decision.
I hope this helps, and welcome to FLORIDA.