A while back I bought some strings from a company called AQUILA they have gut strings and a type of string called "nylgut" which sounds a lot like a gut string but a lot less costly. Another advantage is that they last much longer. As far as I know all of their strings are 120 cm in length and when ordering you need to know the gauge. Very good folks to deal with. I bought the strings for a ukulele and was able to get two strings out of each 120 cm string. If you are interested go to their web page:

www.aquilausa.com

Cap't Bob