Okay, I did a quick search which yielded no useful results, so it's new thread time. I am making what I thought would be a six string fretless bass, but long story short, measured incorrectly and now it's a seven string.

The thing is that I already bought a set of six string D'addario nickel half-rounds and would still like to use them with this bass, but I need a high F string. The only place I know where to get that gauge of string is at
http://www.conklinguitars.com/accessories.html . I don't know how much of a difference it actually makes with that thin of a string, but which brand should I go with, Snakeskin or Power Steel? Feel free to suggest other brands, but last time I called D'addario about gauges they claimed to not make custom ones. I just would like that string to match the sound of nickel half-rounds as close as possible. Thanks a bunch!