Hi gentlemen, i'm in need of info on where to find and the price for irovy ito (would be cool in cotton) and is it possible to go at a foundy and ask to make fittings for katana's (in this case brass tsuba,fushi/kashira and menuki)

and what are the kenji ofr ''light as a feather, strong as a rock'' ?

Bonjour Etienne,

There are many places to get ito, some of them featuring "unohana," "ivory," or "cream" color ito, and some of them you will have to enquire about specific colors. Here is a selection:

Namikawa Heibei Co. (scroll down for tsukaito)
Shadow of Leaves
Fred Lohman
Legacy Arts

The above also sell antique, modern, or cast fittings, and there are many other sources for such. However, if you want to custom commission your own fittings, or have them custom fit to a sword, then you need to contact a craftsman in that field. Here are two excellent makers outside of Japan:

Patrick Hastings
Ford Hallam

Of course there are many more working in Japan, but they tend not to have websites. ;)