Ask yourself this; is running the E85 your goal or a means to other (power or regulatory) goals?
Altering an existing car for the sake of running E85 isn't worth your while in my opinion (certainly not worth the money if you'll be needing an aftermarket ECU for it). However if you're doing a complete engine rebuild/upgrade, new fueling system / wiring loom etc. that's a different story. Some usefull gains to be made with the E85 if building the drivetrain for that use.
I've done a few E85 competition engines in the past. Simply changing your fuel system and ECU mapping and leaving the rest of your power unit relatively untouched won't get you any miracles. It'll maybe get you a small gain in output, but you'll have to drag along a weight penalty since fuel economy will increase by about 30%. Not very convenient when you're doing endurance races.
So forgive me for sounding a bit cynical, but please elaborate on what you're trying to achieve here
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As for the components: you'll need to check the specs of every component in your fueling system for ethanol compatibility. Could very well be some of the parts are suitable already. Check flow rates of every part for an estimated 30% increase (keep in mind you'll want common fuel injectors below a duty cycle of 80/85%). You'll need to be able to alter the fueling and ignition mapping. Wideband O2 sensor not necessary, but needed if you'll want her to run in closed-loop after tuning.
