For several years I've modelled aircraft, tanks, afvs, and figures in 1/35, 1/48 and 1/72 and proud to say that I have never used primer before!!
That being said, before painting, I just usually thin khaki paint with water, then dip the figure in that and wait till its dry .
I have a whole list of HaT Nap French series to order but right now I'm working on 7YW Frenchies, by repainting Zvezda's 1/72 GNW Swedish.
Have you experience in tricorn-era figures? How do you usually do those up? (As their uniforms are more complex than Nap). Do you have a blog?
For your Naps just buy the Napoleonic wars paint set from vallejo if you wish, you can find it at The War Store.com for about 40 dollors, even though i painted imexes awi brits they do have some what more detail then napoleonics, just remember to paint facings and lacings if you want, for syw french a majority on the uniform was white with a wide color of facings heres a link to a very helpful syw website that can help with your french troops, it goes into deatail about every part of the uniform and shows a picture of a soldier and history of the regiment,
PS. i never really use primer either