For my demo game I intent to use Gringo40's excellent Garibaldi range. Although this is for the later conflict much of the uniforms are unchanged for '49.
The French will be Neapolitan figures, as the only difference I can see is the lack of gaiters.
The Republicans will be from the Picciotti and Redshirt ranges, with as much hat wearing troops as possible instead of the soft kepi. I have some bersaglieri too and a unit of Early ACW Union inf in frock coats and shakos to represent some Republican regulars.
One unit which I would like to add but am finding difficult to source are the Lancers of Masina. Wearing a braided jacket and a fez or shako, they need to be fairly big chunky figures to fit Gingo's, although they'll be the only cavalry present.