If you think you're going to stick with trad, I would recommend making your own. You can make a string jig for next to nothing, and spools of string aren't too expensive. Otherwise I've heard good things about Champion Custom Bowstrings (LBR), OliverStacy, and SBD. All three sponsers here at TG. There may be otheres, but those three seem to be the most talked about.
Forgot to mention 1st Class Flemish Strings. I got a bow in a trade that came with one of his strings and it was very well made.