I am still cogitating on this... Though my focus has shifted a bit.
If I happen to win that lottery what I don't play, I'm going to go out and pay for exactly what I posted in my OP.
More realistic is that after I get a Hayabusa (which hopefully happens this year), I'll be looking into getting a cam and transmission gear swap for it.
Now having a Prius, and experiencing the Atkinsonized cam in it, I have to say I like it. And, exactly as I have theorized for years, a 4 cylinder engine has enough grunt to push a car down the highway at <2,000 RPM. A Hayabusa should have no trouble being driven down to 2k RPM at 65mph. (Hence the need for a gear swap along with the cam, as 1st gear would be unusable if the sprockets were swapped to achieve this ratio)