As the previous poster said, you may just have to experiment. I have quite a few pedals running through my rig that weren't necessarily made with bass in mind, but seem to do well nonetheless. They include a few danelectro pedals: Phaser, chorus and tremolo and also an EHX Electric Mistress. Another option (And one I'm really considering right now.) Is to get a Barge Concepts VFB-2, which is a effects loop pedal that has a clean blend knob. Basically, it can allow you to mix in some of your "uneffected" bass signal to your effects, to help compensate for pedals that are low-end or tone suckers.