New Amp help/recomendations?

Hoping some can share experience on this topic. My current amp (ARC Ref 75) while I love the sound is not powerful enough to drive my new speakers - 89db/4Ohm Sonus Fabers. I mean volume is there, but soundstage a bit collapsed, Dynamics a little flat and bass missing oomph speakers are more cabable of.
Amps I am targeting - through lots of reading and research, since I can't get out to listen - are the following:
PSA BHK 300's, Krell 300XD, Theta Promethius, Pass Labs 250.8, Modwright 150se,
Thanks for input/help here.