I’ve had panel speakers since the 80’s and tried to buy or build subs to go with them and NONE are as fast as the panels. I built 7 prototypes ranging is sizes of both drivers and boxes. Used active and passive crossovers and all solid state power. Also tried every position possible.
I also tried, Velodyne, REL(old models) and an old SVS12” and the last is a brand new SVS 2000Pro. Depending on your room, you can probably get close, but….
One thing, whatever you get, make it a sealed box, not ported.
All the best.
JD