Your typical listening range is the same as mine with my 8 watt SET or even when I was using my push pull tube 100 watt (60 watts triode mode which I preferred). I Seldom go louder but have gotten 100db peaks with the Frankenstein SET. It’s funny when the 60 watt was my main amplifier I was so impressed with its organic nature and transparency. Best I’d had up to that point. The Frankenstein instantly changed that perception , 8 watts! More open, natural, less electronic character (relatively speaking). Most significantly, a higher level of pure emotional involvement. It absolutely just pulls me right into the music, deeply. I suspect you’ll be happy with the parallel 300b amplifier approach.
Charles