The shaker 500 has separate amps in the car to run the speakers. The amp in the trunk is 4 channel and serves the 4 - 5x7 speakers (roughly 60 watts peak x 4) and the amp by the drivers kick pannel is also 4-channels serving the 2- dual voice coil 8" subs in each of the doors. These subs see about 60 watts peak per voice coil or 120 watts per speaker peak) Thus the peak rating of the entire system is about 480 watts - hence the Shaker 500 name. If you were to install a unit like you suggest, you would need to rewire the 4 - 5x7 speakers from that unit, and you would loose the 8" subs. There may be a kit out there, from someone like metra or scosche that can utilize your aftermaket head unit and convert the signal to a line in to the factory amps. Not something I would suggest doing.
2012 GT CS Ingot Silver Vert, Edelbrock E-force supercharger with CAI and 3.5 Pulley, Tremec T-56 Mag, Accufab 84.5, Centerforce DF, Billet Yoke aluminum driveshaft, FRPP 3.73 Rear, MRT Performance H-pipe, Bassani axle backs, JL Audio sound, Edelbrock strut tower brace, JPC adjustable UCA, UMI adjustable panhard bar, KW V3 coilovers, Steeda heavy duty front mounts, Steeda rear LCA's, 20" Steeda Spyders with Michelin Pilot Super Sports, Steeda Big Brake Kit ....... it just keeps going.