If you aren't planning on diving into the reefing side of things, FOWLR
systems are basically just like your freshwater...just with the rock being the main biological filtration.
Any breed of clowns would be fine, they are all quite hardy. Here is some good info on them: https://www.liveaquaria.com/category...ish?c=15+27&r=
Just make sure not to mix species. And I'd go for a pair.