Bownut,
I'm not into string making yet but I can suggest you do a search. There has been a lot of talk about the various materials and custom string makers around the country. I could rattle on about some of the better materials, but I know I'd forget some Also there is a lot of info to pick up over at www.archerytalk.com about strings. There are a lot of pro's and competition shooters over there that really know their stuff.
Hope this helps.