Virtually every commercial dive operator that I know of in Palm Beach, Broward, and Dade counties allows divers to cull lionfish, even those that are not usually amenable to traditional spearfishing. Some locales offer “Lion Fish Rodeos” in the summer, so those might be ideal places to find like minded individuals, but you can likely find compatriots on any dive boat in Florida.
Many of the more frequently visited sites are culled constantly, but there are many deep dive sites, (often well below recreational depth,) that are literally overwhelmed by scores of the beautiful invaders. If you’ve got the training, skills, equipment, and inside dope for these spots, then you can harvest to your heart’s delight.