Among the Sunfires, the Signature goes deepest and can provide the most volume. This may be more than you need to complement the Maggies for music. For home theater, they would be a good selection. I have two in my main system which does double duty for music and home theater. The Architecturals have a slightly more stylized cabinet and only the one low frequency driver, designed to be used in a front facing installation like an in-wall location. The regular Signature probably goes louder and maybe a little lower with the passive radiator working opposite the driver.
At the other end of the range, the True Sub Juniors don't really go all the way down with any real volume. They are often chosen for installations where size is the paramount consideration. I use one in my library, improperly located on a bookshelf (yeah, I know -- feh). They do ok with mid-bass material, where many listeners develop the impression of bass presence.
In the middle, the True Sub Mark IIs may be just the ticket to go with your Maggies. They go almost all the way down, beginning to taper off somewhat above the low end of the audible range, but not so that one might really notice with regular music. They should provide adequate volume to go with the Maggies, without overkill, for music material. They probably won't be quite satisfying for dinosaur footsteps, though. I have one in my sunroom system supplementing a pair of stand mounted monitors (no home theater). Good luck.
At the other end of the range, the True Sub Juniors don't really go all the way down with any real volume. They are often chosen for installations where size is the paramount consideration. I use one in my library, improperly located on a bookshelf (yeah, I know -- feh). They do ok with mid-bass material, where many listeners develop the impression of bass presence.
In the middle, the True Sub Mark IIs may be just the ticket to go with your Maggies. They go almost all the way down, beginning to taper off somewhat above the low end of the audible range, but not so that one might really notice with regular music. They should provide adequate volume to go with the Maggies, without overkill, for music material. They probably won't be quite satisfying for dinosaur footsteps, though. I have one in my sunroom system supplementing a pair of stand mounted monitors (no home theater). Good luck.