I'm very seriously considering putting myself on the wait list for a bali steel hand pan. (I'm still waffling a little bit, of course.) If I did, I would have to choose what scale I'd like to have made. They have a list of all their scales here but I think I've narrowed it down to three:

Gaku Joshi
F Bb C Eb F G Bb C Eb

Kokin Joshi
F Bb C Eb F F# Bb C Eb

(these are both common koto scales) (minus the F and F#)

D Minor
D A C D F G A C D

(which is more costly)
( cut for the embeded scale videos )