Maybe not much help (and probably more discouragement than you are looking
for) is CarTalk's take on it:
http://www.cartalk.com/content/features/alternativefuels/flexfuel.html
It says in part:
"Your car's injectors also need to be changed, along with the vehicle's
computer.
The changes are relatively inexpensive when done on a mass production basis
at the factory. But we wouldn't recommend you try to retrofit a car for E85
at this time."

However, that's stuff you indicate you already knew. The warnings are
probably intended more for the casually curious. I wouldn't discourage you
from continuing the search for a package approach. I just don't think you
want to be a trailblazer on this. One other thought - you should decide (you
may have already) whether you are creating an Ethanol/E85 only vehicle or a
flex-fuel vehicle.

Mike