you can use a dual map switch on NA or FI, theres no difference there. Depends on if your EMS will support it.

To upgrade to E85 you have to upgrade your fuel flow capacity by atleast 30%

Example, my car dynod 840 whp last year on gas and 1600's with aeromotive a1000
this year i dynod 850 on E85 with 2200cc injectors, and an Aeromotive Pro this year....im putting a voltage booster inline to let the pump support about 950-1000 when i want it to on e85.