Change of Visa or wait till expiration in order to create a business

Hi Valerie, 

This question is more focused on Visa issues than actual business creation (I’ll ask more on that later) but I’ll give it a shot anyway.  I am currently in France on a Carte de sejour temporaire: Visteur.  I am here officially as a volunteer to help churches in various ways but will quit this in order to start a socially minded enterprise focused as much as possible on bringing answers to alleviate the refugee crises.  I plan on creating a coffee roastery and employing portable bike cafes. The goal is to return much of the profit created back into initiatives aiding the refugee population (and other sans arbi) via education and potentially public housing.  I am currently living in the Paris region with my family and would love to be able to make the changes needed without having to return to the U.S. for more than a short visit. 

Here is the specifics:  My long stay visiteur visa expires in October of this year.  I am traveling to the U.S. this summer and may have my funding pulled from me by the end of June.  (churches in the U.S.A. donate in order to help churches here) I would love to be able change my Visa into one that would allow me to set up a SARL here in Paris. 

so.  1)  Do you know if it is possible for someone to change a Visa (Titre de sejour) or must I wait until my current one expires before I can re-apply for a different visa?
    2)  As an American what visa would you suggest I pursue if I am looking to create a SARL?

Thanks in advance,
Derick