There is no forum for the Via Francigena similar to this one, although I know many of the VF walkers visit this forum for the excellent practical information on gear etc. (I'm one of them). However, there is a friendly
Facebook group that you might find useful. It has loads of good advice and discussions by people walking the VF in 2015. It also has a list of blogs.
The Lightfoot guide to the VF is, in my humble opinion, the best, if not the latest. It has routes for walkers, bikers and horses. Paul Chinn, the author covers the route regularly (he was out checking the San Bernard Pass bike route this month) and provides updates on his website. These include temporary closures, short-term route problems, etc, - the kind of current info you won't find in the guides. The latest Lightfoot guide is, I think, in its 6th edition, so it is well tried and tested. His guide includes GPS info and you can download the GPS waypoints from his website.
The newest English guide to the VF is the Cicerone one. It provides some cultural information - the Lightfoot cultural info is in a guide separate from the actual route guide. However, the Cicerone guide is not nearly as detailed as the Lightfoot one and often excludes stretches of the official route without a mention. You need to know that what is thought to be the original route in Italy is not necessarily the official route as promoted by the
ViaFrancigene.org, which also has very useful info and up-todate info on accommodation on its website. The Cicerone guide is in its first edition and judging by comments in blogs, it is a good guide but some of the route details are inadequate. Also, the maps in the Cicerone guide are schematic and do not provide any information on the surrounding areas, making it tricky if you get lost.
For maps, look for
Monica D'Atti's Via Francigena Cartography and GPS, which covers the Italian section. The map is made up of perforated sections so you just tear off the map for the next section you are walking, making it really easy to use. Somewhere I have info on maps of France and Switzerland, which I can dig out if you're interested.
I'm sure you already know that the VF is very different to the Camino. It is not nearly as well developed or signposted and accommodation can be difficult. There are no official figures, but I believe that while close on a quarter of a million people walked the Camino in 2014, estimates for the VF are under 10,000.
Good luck with the planning!