For high power bass amps, consider the ICEpower300AS1, delivering 300W complete with universal power supply and aux supplies for the pre-amp. Alternatively, for a classic bass design amp see Exicon lateral MOSFETs.
The SPN1001-FV1 single chip digital reverb will add the essential effects with minimum hassle. The SAM5504 adds reverb, distortion effects plus USB interfaces to play along or record, as well as a processor for all the control knobs and indicators.
The THAT4305 Analog Engine will add a great sounding compressor to any amplifier.