Maybe a Colnago Precisa fork then? Miyata were always very deliberate with their builds and geometry on the high end bikes. If it were a 3Rensho, Zunow, Cherubim, or Kalavinka, you wouldn't swap the fork, no?
It's why my 610 is still perfect for me as an awesome all-round bike. It's kind of like when you go out for sushi, if the chef doesn't give you wasabi with your roll, that's how the chef is presenting it as a labor of their craft, not to be covered up by spice.
Just my $.02 of fuel to the fire.
Phil