Check out Magnus Motorsports. They've done high compression builds (up to 15:1) although I don't know how high they've gone with E85. I know that Ethanol handles boost better than the pump gas. Before switching your car over to E85, look and see what gas stations carry it. Buy 1 gallon containers full from each store that has it and have it tested somewhere for ethanol content. If its lower than 75%, I'd say its not worth even trying.
Big 16G, FMIC, Greddy BOV