Situation: Originally I was lead singer in my band and things were going great and all till our bassist quit. We looked for a bassist, but none could be found. My guitarist's solution, make me the bassist. Which is cool, I enjoy the bass, I just have no idea about anything that has to with the bass. I sold my guitar and now I have about $600 to spend on an amp and bass. So any suggestions on a semi-beginner bass and decent amp?