Warm, Deep Stage, S.S Dual Mono Amps ?

Looking to step up from my B&K M-200 mono's, anyone familiar say, with semi-older Rowlands, Classe, or similar classics ? Speakers are Dahlquist DQ-30I's with 91db,& 4-ohm nominal. I want to stay with dual-mono, (2 chassis), system & cables are configured for it.