Check with a company called "Tractor Supply" They are a supplier to the "hobby" farmer. They have a large selection of wire. Saw some different size brass wire. Some a fine as heary sewing thread.

One other option I would consider would be using some of the "braided" fishing lines in the 50lb test range. The braided line could be used as snare material, fishing line, thread to repair clothing, possible suture materail. I try to make things in my survival kit multi functional. Helps to cut down on weight or gives the option of carrying something else.