Your Sunfire HRS12 subs (MSRP $1,300 each, definitely not cheap) have a high-pass filter (subsonic filter) where you can filter out frequencies that you cannot actually hear (below 25Hz),right?
Are they also sealed (instead of ported)? Sealed subs are much less likely to bottom out or be damaged due to high levels of low frequencies (usually below 20Hz).
In this hobby it’s easy to be overzealous and overkill with amps and subs, among other things.
Those Sunfire are expensive subs and since they sound great, there is no reason to replace them.
IMO, it's usually better to have multiple subs than one big sub.