Options :1) http://www.soundqubed.com/HDS300-Bundle_p_234.html
2) subwoofer :http://store.soundsolutionsaudio.com/products/sundown-audio-sa-12-600w-sa-series.html
Amp:
http://www.onlinecarstereo.com/CarAudio/p_34594_Precision_Power_BK13001D.aspx
Or this amp with that sub : http://www.amazon.com/gp/aw/d/B005KW10ES?pc_redir=1403902327&robot_redir=1
This is not in any certain order.