I went from gas to ethanol this year and I didn't change a thing other then larger injectors. You don't need to change fuel lines or any other item in your system as long as you have the fuel pump to supply it. I do believe you need to run a different carb (sorry, I am a fuel injected guy) but there are some on the market now that can support the increase in fuel volume. The average that I have found is you need to increase fuel 30% to 35% from gas. Air/fuel will vary depending on your application, you can't say what a range will be because every motor is different.
In my testing, I have seen an average gain of 8% to 10% more power. This is all on E85, not pure ethonal or E95 like most place sell.