So I am working on preproduction for my band's next record right now, and I am currently using a 25.5" scale 7 string tuned to F#C#G#C#F#A#D#. It works for preproduction, but I would like a longer scale instrument, and have been looking into the option of an 8 string, but can't figure out what an optimal tuning for an 8 string would be with the E string in C#. What would you guys suggest? My best idea so far has been F#C#C#...which obviously isn't that great an idea (although two C#'s in the same octave might sound interesting?). What could I do with that 8th string (taking into account string gauge, tension, intonation and the rest)? Thanks.