So, several days of diligently - ahurr, pardon the pun - searching up travel routes between Paris and the southern towns that Hugo cites as our amis' homes, I finally encountered Reichard's "A Descriptive Road-Book of France" and thought to share. Written conveniently in 1829 by Heinrich August O. Reichard, it's intended as a travel guide for visitors coming to France from England, but contains pretty much everything you might need for your 19th Century Ami roadtrip, whether it's home for Christmas or to spend the summer in the countryside. Additionally, there's some excellent stuff about living in France in 1829; how much rent and fuel costs, as well as taxes, charts of relative expenses for various things, etc.
Available here as a free ebook: http://books.google.ca/books?id=Iz2Ae5zEldYC&pg=PA33&lpg=PA33&dq=french+diligence+coach+Toulouse&source=bl&ots=QMRW753Dff&sig=_SxNA5QVPmQya1Tm--HsUClHn10&hl=en&sa=X&ei=-n0gUdjfOoX29gTTi4DIDA&ved=0CEwQ6AEwAjgK#v=onepage&q&f=falseA Quick BreakdownPgs 1 - 7:
A description of what the traveler ought to bring with as far as money is concerned, in order to cover any sudden expenditures. Also features a handy breakdown of French currency/worth against the British pound c. 1829. Pgs 7 - 9:
Luggage, how much, what kind, everythin' you need to know 'bout luggage. And also the conversion between British weights and French weights. Pgs 10 - 20:
Fares and specific information about traveling from England; what time coaches/boats leave at, how to get directly to Paris. Pgs 20 - 21:
Duty (and tipping). Pgs 22 - 24:
French Inns, how much they cost, what to expect from them, etc. Pgs 25 - 33:
Methods of travel; Posting (and how it's done), Cabriolets, Diligences, Traveling With the MailPgs 34 - 46:
The Diligence Directory; the exact addresses of the diligence offices for each coach traveling to the city of your choosing, as well as a list of the more principle diligence routes. Pg 47:
Traveling via canal, traveling on horseback, traveling by personal carriage. Pgs 48 - 49:
The expenses of living in France, rent, taxes, fuel, how much necessities (bread, meat, etc.) cost. French climate. Pgs 50 - 520:
Routes from Paris; a description of where each coach stops between cities, where they depart from, as well as useful descriptive information about each major town in France from an 1829 perspective. This includes comparisons of prices to what they are in Paris, population, the homeless, notable buildings and sights, etc. Pgs 521 - 565:
A clickable index, you can select which town you're most interested in seeing and go directly to that page within the rather hefty "Routes from Paris" section.