There used to be an excellent forum for Matsumoku built guitars which had tons of catalogue scans, but unfortunately, I can't remember the site address.
For the roundwound strings, I'd have to recommend D'Addario Pro Steels EPS165's. Long lasting, bright sounding, and (IMO) really suit "mid focussed" basses (Ric's, Wal's etc.).
Haven't tried a 6 string (to be honest, I don't particularly want to).
Haven't tried an Octave Course 8 string (tbh, I really particularly want to!)
Wouldn't mind trying a Wal and a multi-scale bass.