I would probably sell the two JL F113 and buy one JL F112 (or keep one F113 and sell one), crossed over to the HT3 (or SoundScape) at 40-60Hz. Take the strain off of the HT3 (or SoundScape) for the really low movie effects, but still have enough for dinosaur stomps and exploding planets.
Since you don't really need multiple distributed subs for music, it seems like a bit of overkill for HT, particularly with the HT3 (or SoundScape) splitting the load.
Steve