There is no question the zx7 frame is stout enough for the task...probably the most robust bike ever made (the engineers definition of "robust" is: too heavy to lift).
Anything can be done with enough money and time. But to do it right is not just about money. I see custom stuff all the time, and being an engineer and a gear head, I cringe at whimpy brackets with weird joints and high stresses, poor welds and so on.
It might be fun to try.....maybe if I find a frame cheap next year.
Dave - its a shame you live so far away....I am sure I could learn a lot from you....in fact, it might be dangerous.