Well if it was me, I'd go for a chambered mahogany body and a 5 piece laminated maple (3x) and mahogany (2x) with graphite reinforcing and a super thick compound radiussed ebony fingerboard. For pickups I think humbuckers with parallel wired coils with coil switching to allow single coil use, to allow for Wal and Jazz bass sounds, and a preamp with sweepable mid control. But if the bass sounds right then why not keep it passive?
The mahogany will give lots of midrange growl with enough maple to keep the neck from being too seasonally temperamental. The ebony fingerboard will provide some brightness to the top end without it sounding too bright. The fingerboard needs to be thick enough again to reduce the flex so that once the fingerboard has been radiussed and flattened under simulated string tension, it will play with super low action given your choice of strings.