Thanks all for your help; some good suggestions. The plans I am using are from a book called "Dulcimer Building Start to Finish" by Neal Koch, which is excellent. The subtitle is "A Modern Hammered Duclimer Design" so its not an attempt to build an antique. He suggests brass only for the three lowest bass string pairs because it "has a subdured tone and is smoother sounding" and phosphor bronze for two other bass pairs. I thought about using loop end strings but that would be quite a bit more expensive if used throughout, and if I used only a few loop end strings they would be coming off the center of the hitch pins while the others are wrapped around and would come off one side which would mean not all the strings are parallel, which might not interfere with playing but aesthetically might be a problem (or not). Perhaps I'll try steel piano wire for all the strings to start, and experiment with loop end strings for some of the bass pairs, if I can't find brass easily.