@Haiawata, that's helpful! Where I dive in Portobelo, up on the Caribbean coast, it sounds like it will check some, but not all your boxes. In the wet season (June-Dec), the visibility can be quite variable. Good days are 70'+, bad days are around 5-10'. It just depends on how much rain has fallen the past day or two. I always dive the wet season and would say we average 40'. The dry season (Jan-June) has consistently better visibility due to the lack of rain.
The reefs will not be as good as you've seen in Cozumel or other places in the Caribbean. The reefs are a bit degraded and have less coral cover than other places in the Caribbean. But, there is quite a bit of life and I've often been surprised by the occasional school of permit, nurse shark, or huge snapper that swims by. There are constantly lots of small critters as well. There's also a lot of topography. A number of dive sites are mini walls and you can see some cool geology, where it's clear that the cuts in the reef, dropping off the wall, are old river channels that were once above sea-level.
On the plus side, I cannot recommend enough diving with Golden Frog Scuba. The owner (Rey) runs a tiny six pack boat, and guides every dive. He'll stay with you and point out things, or alternatively, give you your space and just let you kind of follow along and do your own thing at your pace. Sometimes we have other folks on the boat, but commonly it's just my buddy and I diving alone with Rey. The lack of a crowd is pure joy!
Topside, Golden Frog Scuba operates out of a little boutique hotel in Portobelo. It's a tiny little place on the side of the road, but they have a great little restaurant on the premises and great views of the water. They make an amazing seafood curry! Just down the road is a great restaurant/bar, El Castillo, also on the water. The town of Portobelo is small, but there is a lot of history (old forts) and some great local Panaderias.
It's off the beaten path, to be sure, but I've been doing it for several years now and I love the experience. If it's something you decide to do, Rey can help arrange logistics. Likewise, I can make suggestions for a driver from Panama City (feel free to PM me).