You might consider a pair of Entec subs as well. The LF20s were originally over $6K but might be had in your budget. Check here at Audiogon.
Alternatively, the Celestion System 6000 gave great sound with my CLS, but doesn't have the ultimate volume of the the Entecs.
Alternatively, the Celestion System 6000 gave great sound with my CLS, but doesn't have the ultimate volume of the the Entecs.