1 board quiver... We will all have a different idea on this... You need a board that suits the waves that like to surf, where you live!...

Kelly Slater pretty much rides 2 boards... 1 boards for like under chest high, and 1 board to over that... (excluding big waves guns, etc...)... Obviously Kelly's 2 boards of choice are shortboards.
I could do a 1 board quiver... I think the 9'6 Dick Brewer is very close to being a 1 board quiver...
Otherwise, I would blend these 3... 8'6, 9'0, and 9'6... I would blend the 9'0 and 9'6 together, as a 1 board quiver... I would be very happy!
For me, the pointier nose handles the bigger waves better... And that's what I like to ride!