Getting 2 subs

I use to great satisfaction 3 different SVS subs in my main room. A SB4000, a SB3000 and a PC2000 Ultra. The 4000 crosses at 60hz, the 3000 at 80hz and the 2000 at 100hz. After playing with the gain for some time it is now dialed in seamlessly. You never hear any indication of a subwoofer and yet there is a dynamic that is hard to explain. The interplay of the subs does magic to my bottom end and the music is captivating. 

The 3 different SVS subs is something I considered, now that I know it works, that’s probably what I’m gonna do,  only gonna get 2 subs, which should I get ? The sb 4000 and the 3000 or the 4000 with the 2000?

In my experience, the 4000 and the 3000 seem to pair better. That may be because my PC2000 is a bottom firing sub. I have often wondered how the SB2000 and 4000 would pair up. The quickness of the 2000 and the crazy extension of the 4000 would seem to cover all the bases. Either way, have fun and play it loud. 

I switched to 2 subs about 2 years ago and will never use just 1. I think they should be the same model. 

A pair of matching subwoofers is better, more balanced for the listening room.