Best company structure for shop owned by couple.

Hello Valerie,

First of all, I hope that I am posting this under the appropriate tab, otherwise feel free to move it to where it belongs.

My wife and I have recently moved to France with our child. We want to open a store here, more precisely we want to open an epicerie fine with a connected web shop.
Apart from that, we also want to offer some other unrelated services.

We would therefore like to set up a company, consisting of two sub-companies; one for the epicerie, and one for the other activities.

We were thinking of a SARL or a SAS structure, and we would like to own the company 50/50.
We also would like to have good social security.

We do not think that the turnover will be very large in the first few years and, and we probably need to take out a low monthly salary. Apart from that we plan to reinvest as much as possible in the company.

As far as I have understood it a SARL is best for a small turnover and if we want to take out a monthly salary and it is easier to reinvest in the company.
The SAS structure is good if one can do without a monthly salary, because of the low taxation on the dividends at the end of the year. Also a SAS structure offers a better social security.

I suppose both structures could work, but which structure do you recommend on the given information?
Is there a third structure that you think would work even better for our plans?
Would there be any economic benefit if the epicerie with a lot of expenses, was owned by one of us, and the other activities with basically no expenses was a separate AE owned by the other person?

Lastly I have a question regarding timing; do SARL or SAS companies need to have separate company addresses, i.e. not ones home address? If that is the case, what is normally the procedure when opening a store, is it normal to rent a location before even registering the company? I would of course prefer to have everything registered before renting a location.

I hope my questions are understandable, as it is all very new to me.

Thanks in advance for your advice.