Help fellow AV designers

I have a client that wants her home theater to only show the screen (probably a 55" LED)even though it is a TV rm. What are the best sounding speakers that are practically "invisible"? They currently have some cheap flush mounts in the front wall just under the ceiling (so much for hearing any highs huh). They have(3)flush mounts in the ceiling for the effects. I have recommended going to a (2)channel design but may not succeed unless I can come up with an alternative front pair of speakers that she likes the looks of. They would have to be tiny and she is against seeing a sub. She is a minimalist and likes a clean look. I can install the system in a cabinet behind the TV wall in a Study. Any help is appreciated.