I am putting together my first car audio system and i have some component Infinity Primus PR6500cs up front along with an Image Dynamics ID12 D4 V.3 subwoofer in the back. I upgraded to a Kenwood KDC-BT558U for the head unit. All of this going in a 2001 Chevy Tahoe, but i am missing the last part an amplifier to amplify this stuff. What would be a good amplifier to power the sub and two speakers that is under $250. Thank you for your time. Jeff