SA-12? No personal experience. Just know that it's good and has a somewhat lower RMS rating. Do subs with higher RMS ratings have stiffer suspension or are they harder to get moving? Never really new the answer to that haha. Prolly sound like a noob.
Sundown audio sa 12s are very nice and will deliver the sound your looking for. The sa 12 recommends 1-2 cubes so you would be really happy since your box matches the sub