It's not so much about towers replacing the need for a sub, it's about their ability to "fill out" the freq range when listening to music.
If you listen to that much music, I'd go with towers, and because of your size of room (do you have it set up to where your screen is on the short wall? or the long wall?), I'd say go with 6T's. If you're <13 feet from the screen, like if it's on the longer wall, then 5T's would probably suit you just fine.
But you're right...tough to make a bad decision here.