Those injectors should work just fine. I use a Split Second AIC1 controller and R4 software for my aux fuel control. The software is a little dated but it does the trick.
There is a used aux fuel kit listed in the classified section at a hell of a good price. It has everything you need to convert to E85 minus the tune of course. I'd be all over it if I didn't already have one.
https://www.mustang6g.com/forums/threads/e85-aux-fuel-kit-tune.133267/
The vibrant resonator will definitely cut down on the drone and crackles and also makes the exhaust tone a bit deeper. I say jump on it. If you find that it is still too raspy or has too much drone, you can always swap out the small bottle resonator for a larger vibrant ultra quiet resonator...
Fwiw, I talked to a friend of mine who is a tech at a large dealership in Tulsa. He told me the decision isn't up to the dealership, but rather it is up to Ford. He said they'll turn it in to Ford and its up to Ford if they want additional info. Sometimes they'll ask for ECU data and...