Also, try a wide strap, suede or something like that. Like this?
Very psyched that you got the bass!
Regarding strings, the Stanley in my pic is strung with D'Addario Chromes (flatwounds) - although a lot of the Alembic image is of Stanley Clarke and a very bright sound, actually Phil Lesh and Jack Casady were much earlier and they used flats (Pyramid strings) - might be fun to try.
Chromes tend to be on the bright side as far as flats are concerned. TI Jazz Flats are renowned for their sound as well as their low tension. LaBellas are pretty traditional. Rotosound flats strike me as very high tension. I just put GHS flats on my Fender - it's long-scale, but they struck me as a bit lower tension than the Chromes that it came strung with.
Definitely check the thread moderator Dave linked to - short scale strings may not cut it, depending on the brand. Also, rounds may well be fine - the mighty Alembic filter may well allow you to fit in to any situation!