It's been a long time and things may have changed, but Tikila and Ernesto's weren't playing 'murican music the last times I was there.
Been to Tikila many times with friends during sunset, Ernesto's too for that matter. The only problem with both of those places is that they have a "south" wall. Sunset viewing is better at Tikila, though Ernesto's has some tables away from the wall on a sort of deck to the west as I recall.
I don't know the layout of BA, but I'm surprised you can't watch and listen there?
Edit: I don't drink Gin and Tonics, but I'd be surprised if you can't get one at either place.