Sounds as if a compact, integrated EL-84 amp might just fit the bill for around 20 w/ch. There’s a newer Quicksilver and or older, refurbished Scott, Heathkit and Eico integrateds. EL-84’s were often the tube of choice back "when"....they still sound great! - Still, choose the right speakers, that you like & fit the room size, then choose your suitable amp (tubes generally like 8 ohms or more).