I am super super confused.
You are pretty much building a preamp as separates. Just get a great preamp. You literally just described the reason preamps exist.
Otherwise I suggest the Schiit Loki, with the tone controls set to neutral would work.
Buffer amp no gain
I would like to put a buffer stage between volume control and power amp to ensure impedance matching. I like the look of the First Watt B1 but don’t need the volume controls.
My volume control is a passive ladder type with expensive resistors, silver wired etc
So my question is, can I buy a buffer with phono inputs and outputs but no volume pots. Either valve or solid state is OK.