bi amped speakers in monsoon system

My 2002 Pontiac Grand Am GT with the Monsoon system has a blown rear speaker.  The OEM speakers have the 4 wire inputs.  The local installers are recommending a standard set of 6X9 replacement speakers wired to carry the low-frequency audio.  The high-frequency audio would be handled by the front speakers.  Apparantely the bi-amped speakers are not stocked by the local guys and they like to sell what they have on the shelf.  Will this set up sound good?  I don't want to go with a whole new system, I just want something that sounds good, it does not have to sound great, just good.  Thanks.

Soundstream sst6.9 have two sets of inputs. Highs and lows.

I looked up the SST6.9 and it comes with external crossover.  Should I just not install that since I believe the Monsoon system already has a crossover feature built in.

Good. point. You don't need the extra crossover that comes with the speakers. Just make sure you use the right speaker outputs...as in make sure the tweeter output goes to the tweeter and the midrange/woofer goes to the woofer.