Depending on your goals and budget. Sounds like your ready to jump to E85. Make sure you have a tuner and a unlocked pcm. Buy credits if needed.
If you want to make the leap, go for it.
If you want maximum HP and to "Do it all at once" You may consider the lower pulley, headers, cat delete, and 3" pipes of your choosing the rest of the way back and a open air intake of quality. Bare in mind, it will be loud, angry, illegal (technically),and generally a race car at that point. So if that's your goal, go for it. If you want something that still makes your heart race but is easier to live with daily. Maybe not.
Also, I reccomend getting a 91oct or 93oct tune with you E85 tune. It really helps if you ever take the car on a road trip and E85 isn't available along your route to be able to flip back and gently run pump gas to get you there.
Just a disclaimer, I'm no expert or anything. I'm repeating what ive seen, read, and been told by others. There's some good guys here that will help you for sure. Please don't rely on my response only.
My cat is running a 2.65 pulley and 100 oct tune. I'm looking at finishing the job and jumping to E85 aswell and am just telling you what I've come to understand for myself.