Ok so I am ready to get the ball rollin on the sound system. I have my mind made up on running one 12" shallow mount sub under the backseat. I will swap out all factory speakers and add 2 tiny tweeters as well. All I need to know is what kind of amp I need to get sufficient power to everything. I only want to run one amp. So tell me how many watts and channels I need to do this. Thanks in advance!