As far as phasers go, both the Phase 90 and Small Stone sound great on bass. They both have set depths, and to my ear the depth of the Small Stone sounds a bit deeper and funkier (especially with the color switch engaged), while the Phase 90 is more smooth and light. Both are excellent choices IMO.
As far as octavers go, it really comes down to personal tastes. Analog vs digital, the tone, the form factor, and of course the price.

The old favorite is the OC-2, but there are more than a few people who have the new MXR BOD.