I am using a Coda CSIB V1 with the HS speakers and I have no urge to try tubes or anything else. I would also suggest you look at Luxman integrateds as well.
Amp & Pre or Integrated for Dynaudio Heritage Special
Currently have a PrimaLuna EVO300 integrated and looking for something that would do these speakers justice. Would probably prefer to go the integrated route but not opposed to separates. The Dyns are extremely fast and somewhat forward. Don't want to lose the PRAT which I love but need a sweet top end with good power.