I will orientate on 3.1. and leave out most of the applications, games, demos and so on. What I want to keep are the base parts like libraries so that a application or game that runs on f.e. the big version also runs on the light version.
If possible I want to use Scalos to replace Wanderer that is still not enough optimized for slow hardware, what will certainly change in future.
My thinking was that a super light version of AROS would be good to wean Amiga classic users off the old AmigaOS and into AROS.
Have you considered Jason's Workbook as a desktop?