Hello, I have a 2001 tahoe with everything stock, non-bose but w/ onstar, i was looking at these subs, http://cgi.ebay.com/NEW-MTX-Car-Audio-2-12-Subs-Car-Amplifier-Amp-Sub-Box-/230493520052?pt=Car_Subwoofers_Enclosures&hash=item35aa7c00b4#ht_4139wt_1139 , but i am not sure if they are a good...