I actually already read through your build. Unfortunately I have the step through version or I'd try to use the center triangle. How relevant would those components be at present though?
I have an Electra Townie &D that I'm looking to get converted due to my difficulty climbing the mild hills in the immediate area near my house in the Boston area.
I have no real max speed requirements. I am honestly fine going at normal pedaling speed with a mild boost if traffic is on my tail...