Are you troubled by the Speakers being a little out from the Wall your TV is mounted on? How would wall mounts solve your problem?
I would keep the Towers, and absolutely focus on getting the Subs replaced. Also, moving the Subs off the Front wall might be a great option. You can place them strategically in the room to get better bass response and perhaps really increase the feel for movie watching.
You could then slide the towers in a little, though I wouldn't push them in too much. Absolute minimum distance between towers should be 6', 8' is always preferable for good stereo separation.