I would use the altered tuning that works for the sound you want. What is the purpose of using an altered tuning?
Michael Manring is the king of altered tunings. Check out
http://www.manthing.com. He has a whole page of altered tunings. They are 4 string tunings though.
Michael Hedges used a lot of altered tunings. He was a guitarist, but I don't think that matters.
Read this article:
http://www.zonguitars.com/zonguitars...ed_tuning.html
Tune the strings to make them sound the way you want them to sound. Try different intervals between your strings. I don't think anyone can give you a list of tunings to create what you already have in your head.
Joe