It may be a little too early to settle the problem of the legal form, which is a matter for specialists, especially since in this case the capital is important: several houses, several jobs.
From what I learned recently, the law of 1901 is not the foot
, nothing prevents to use the statute of ASBL or cooperative society. But, I repeat, it's a matter of pros; and no need to speculate until we have defined what we want to do .....
The range of solutions is wide, nothing prevents mixed solutions: an SA for heritage, an ASBL for the mutual aid structure, etc.
You might as well resign yourself: there is a lot of work to do, I think that currently, it is the debate that is interesting: a meeting must be planned.