I thought that I wanted what you described (as I too am getting older).
So I got an eD 8" sub getting 260wrms. . .
Recently I've been playing with the idea of getting a single 15" on 400wrms.
Short answer - Don't go with just an 8"

From where you came, I think a single 15" will do you well. So when you really want to crank it up you still can.

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Nostalgia just isn't what it used to be.