Well ... I guess one way to go about it would be to go through some online videos of people playing the kind of music you're interested in, and see what they seem to be playing. There are a variety of accordion playing traditions in France, and a broad enough range of types of accordion that some people might disagree that these are accordions at all.
I guess by keyed, you mean piano accordion. That's a chromatic instrument: all notes are available, and furthermore the same notes sound whether you push it close or pull it open. The chromatic button (CBA) is also chromatic, of course, it's essentially the same as piano accordion. French players use both types, though in the "musette" scene I think there might be some preference for CBA - and when you get into it, there are preferences with regard to tuning, unusual variations on the left hand Stradella layout, etc., but you won't find any options of that nature in the US. The French also use diatonic accordions - only the notes of a scale (or two, and typically different notes on push and pull.) On this site we don't pretend to know anything about diatonic accordions, but you can find that sort on melodeon.net.
As to where you'd look -- I gather you're in North Carolina? maybe not so much going on there, appears to me that most of the retail action is in the northeast and midwest. That's for regular accordions, i.e. chromatic. Liberty Bellows in Philadelphia apparently has a pretty big selection and extensive online documentation including videos.
