I just switched to E85 on my 2011 STi. I went with the DW65c fuel pump and FiveO custom 1000 cc injectors. They were really easy to tune and they still idle and drive really nice on regular gas. I'll be on the stock turbo for a couple more years at least so 1000's made sense to me. There is a little room for a turbo upgrade but I would have gone 1200's or 1400's if I had bigger plans for it sooner.
I haven't dialed in any extra power yet on my tune but its running really well on E so far except for the horrible gas milegae of course
I'm waiting for a new Wideband to show up tomorrow so I can fully tune it.
Your mods should be plenty sufficient for some nice gains on E85. A lot of people switch to an interrupt style boost controller as well such as the Grimmspeed EBCS. It helps control boost a lot better.