Nice project, great write-up!
Software is tough though, even the OpenMoko Neo FreeRunner had 128 MB Ram, and Illume was dropped from Enlightenment since. (There’s a note to revive it in the TODO file, though.) Of the ongoing “mobile Linux UX” efforts, Sxmo or Maemo Leste might be adaptable - they come in at below 200MB RAM on 2GB PinePhones.
Additional caveat: All these UIs have been made with touchscreens in mind.
