I am thinking about purchasing a pedal and I have two in mind, the ODB-3 (Boss), and the CEB-3 (Boss) bass pedals. The ODB-3 is a distortion/overdrive pedal (btw, would someone explain the difference to me?) and the CEB-3 is a chorus pedal. I like to play blues, grunge, and rock on my bass. Which pedal would be most effective for the type of music I play? Also, which would sound good with the tiny Crate (15 watt) amp I have and my active custom-made Peavey bass (year- 1998)? I would buy an amp, and I am going to soon (probly a Fender, might ask for advice on that too) but I have a birthday coming up soon and need to know what to ask my parents for (I'm 13, keep that in mind, I'll be 14). So if you could help me decide that would be of great help. Those are the only two pedals I have in mind, so pleez don't suggest auto-wahs or flanger's or any other kind. Thank you very much for your help.