BB614 is nice, havent tried the RBX760a yet.
The bass body are both alder(760a with ash veneer) and neck also maple with rosewood fingerbd(bolt on).
BB614 - PJ pickups, 3 band eq(bass, mid, treble), 21 frets
RBX760a - Humbucker pickups, 2 band eq (bass, treble), 24 frets
Give it both a try and see which sound suits ur music most.
Cheers,
Ben