In novels, what would be a good english translation for "師祖"?
If you're going to go with a romanization of the English such as "sifu" you should probably go with standard Pinyin (i.e. Shizu）, rather than some other lesser-used romanization system like Wade-Giles or Yale. Perhaps "Grand Masters" of "Founding Masters" might work well in English. The term seems to be plural (although I have no context) so make sure you use the plural form.