For bass:
IE Nimbus has HPF and LPF for the effect, and they work really well. But it is quite hard to find and may cost a lot. Because the reasonable amount of the effect is small, any reverb is most likely good, but use it sparingly. That Behringer is worth trying.
For vocals:
Start from t c helicon. If the mixer supports stereo, consider a stereo unit, or mono for the vocals only.