You are not, as a jazz player, going to find simple arpeggiation quite what you need. In fact, for my tastes, I rarely find even the arrangers' bass lines inspiring for jazz, it's that whole question of 'how does the arranger know the NEXT chord in advance', because that's how a bassist thinks when he (or she!) is playing, and it affects the line drastically. Arrangers, because of the nature of the beast, can only do simple, repeated motifs, rather than true voice leading. If you want bass and drums to do the true jazz thing, you are going to have to think of SMFs or mp3 players, and program what you want in advance, otherwise, what you are already using is by far the better choice.

On the other hand, if your taste in jazz tends towards the trip hop and acid jazz school, a MotifES or Triton, with a lot of work (!) might do - but if you want to swing or go straight ahead, sorry, arrangers are IT.....