Most places offer formules. I have never noticed any difference in the portion size of an entrée or plat in the formule, as opposed to ordering à la carte. The main difference is that not every dish on the carte is offered in the formule.

If you prefer wine as an apéritif, even the smaller places offer several choices by the glass or in a carafe. I have only seen the generic "white" or "red" in small ethnic restaurants.

Usually the 3 or 4 course menu of the day is a special deal - more courses for a lower price. Almost all places will allow you to order a la carte. But, you do need to realize that portions in France are much smaller than in most of the US - more like half the size - and only one course willlikely not fill anyone up.

As for aperitifs you can get them anywhere - but they are not required. I often order a Kir when sitting in a cafe/relaxing - with no meal coming at all.

I love the kir or kir royale. Martinis (even properly gin) will not really be "satisfactory"--plus EXpensive!!