I'm pretty sure Nolly uses d'addarios nowadays. He's on their artist page and it says he uses their EXL165SL set and probably a single .145+ for the g#. Maybe d'addario will make the super longs fit the dingwall 37" more suitably with Nolly onboard.
Also nice bass! I have one in tangerine...
Yes, five-string bass provides you the low B. A six-string bass would also give you that low B plus a high C. So if you're recording with low tunes a five-string will do the job. A six string bass compared to a five-stringer would only give you an extra high string.
But since you're playing...