Hi, I just spoke with a buddy who uses a pair of Krell MDA-300s to drive the woofer towers of his modified RS-1Bs. He uses a Dahlquist active crossover in lieu of the Infinity crossover for a couple of reasons, one that the latter is out of commission and the other that it won't work with the MDA-300s which are quasi-bridged. He said he had tried both the KRS-250 and the Eagle 7A and found the MDA-300s to be better than either. I can't say how the others would do. You want something with generous output current capabilities and ample heat sinks.
Brian
Brian