Second recommendation of Luxman L-509x. It does indeed have the power needed to drive the 3.7's. Keep in mind that it's doubling its output in 4ohms and nearly doubles AGAIN into 2ohms.
For reference, I'm driving my Wilson Watt/Puppy 8's with a Luxman 590axii. It clearly outperformed a very expensive separate setup with ARC Ref75SE, PSA BHK pre (yes, tried the ARC Ref5, but the BHK was better). Should say something about the quality of the Luxman integrated amps...