It is normal to buy bamboo as plants, (rather than roots). Propagation is mainly by division and root cuttings, since seed is rarely available for many species, and propagation from seed can be difficult, as you found out. Because bamboo propagation is difficult, bamboo plants tend to be expensive. Maybe you are asking people to supply you with root cuttings for propagation, but that isn't easy either.
I would presume that you can buy bamboo plants in Italy, but having had a look around the web.it I didn't find any bamboo nurseries in Italy. But I did find a couple of italian bamboo appreciation clubs, so perhaps they could advise you how to source bamboo in Italy.
You can certainly buy a wide range of bamboo in France, mainly in damper parts of France further N and W than the areas close by Italy: here is a list of specialist bamboo nurseries in France:
http://www.pommiers.com/Pepiniere/bambou.htm
You'll be able to source a wide range of Phyllostachys from France, and many others. But I doubt you'll find any Dendrocalamus, Gigantochloa or Guadua in France, because they are tropical/subtropical bamboos and aren't very hardy. Indeed being hardiness rated down to -1 or -2C, according to http://www.americanbamboo.org/Specie...blesIndex.html I wonder if they would survive in Tuscany anywhere other than close by the sea. They may also require a lot of water.

I would suggest you post on http://www.bambooweb.info/bb/index.php which is a much more active specialist forum.