I think that this is the best starting point, so as to test the idea in Real Time, without too much initial risk. There's quite a few folk here on this forum, willing, I'm sure, to support your first steps in the venture.
As to a 'speciality' : may I suggest that we see a lot of folk disappointed that 'such and such' a model is not available in 'lefty' format. Maybe it could be an option to 'clone' a 'righty' bass into a lefty version, if a lefty player said what he/she would be interested in..? Just an idea.
For my part, I like semi-acoustic instruments, but that's maybe a whole different ball-park (and Our Eldest would be my first port of call; he made his own guitars, and has made (from scratch...) a few for friends or folk that know us..). It can be done, but it's really a Labour of Love, rather than a revenue stream, to be honest.
Another thought... How about offering especially light-weight 'fender-ish' basses, by chambering (drilling holes..?), lightening a bought-in body..? As long as it doesn't induce the dreaded neck-dive, it's a way of filling a gap in the Market, no..?