This is probably a long shot, but I'll ask anyway...

I was having some trouble with my back wheel going out of true every time I rode it, so I rebuilt it with double butted spokes for more tension, and it's working out perfectly.

My issue now is that I had to buy two boxes of 100 spokes, so I've got 168 spokes sitting on my bench feeling unloved. I thought it'd be cool to get some more hubs and rims and build a couple of spares (plus it'd be good practice).

Problem: I can't find the same hub except on a complete wheel. I suppose if I was serious, I'd buy the whole wheel and rebuild it with the double butted spokes, but I'm not that hardcore.

Finally to my question: does anyone know of a reverse-spoke-length-calculator? Something that could suggest a hub/rim combination for the length of spokes I have. Or should I just forget about it and buy more spokes...