Ideal Sub pairing for Quad 2805s

Looking for fast, musical sub that can keep up with the speed of the Quad 2805s. Heard that the Wilson Benesch Torus is an amazing pairing that works perfectly with the Quads and brings out the highs and midrange even more!
The only problem is that I don't want to spend $13k at this time.
Has anyone used the REL Gilbralter G2 with success? Intrigued that the carbon fiber drivers of the G2 may be fast enough to work with thte Quad electrostatics.
Any other ideas people have used with success? JL Audio Fathom f112 (certainly a great home theatre speaker)?
You might also consider the new ML BalancedForce 212 or 210's. Designed to work with stats, so very fast!
I'm using 2 rel 328's in my setup, and they work wonders.
I'm using horning aristotles which are fast (not as fast as an electrostatic), but I recommend buying one for each speaker. Very addictive once you use them.
Used a pair of REL 505s and later the G1s with the 2905s.
Highly recommended