you could go all the way? But why? ALrigth JL's Are good, get one 10 that's enough Boom, then change out the front speakers to a nice Pioneer TS-C1653 Then for the back switch em to Pioneer TS-A6995 4-way Speakers that handle 2-80 RMS, 300 Max Watts they'll set you back about $150, but trust me its worth it.
Specs and Features of Pioneer TS-A6995 6x9's
Sensitivity 93 dB
Frequency Response 25 - 32k Hz
RMS Power Range (Watts) 2-80
Peak Power Handling (Watts) 300
Design 4-way
Tweeter Design (1) Dome, (2) Cone
Tweeter Composition (1) Ceramic, (2) Poly
Woofer Composition IMPP Rigilite
Woofer Surround Butyl Rubber
Impedance (Ohms) 4
Top-mount Depth (Inches) 3 1/2
Bottom-mount Depth (Inches) 3 7/8
Specs and Features of 6-1/2" Component Speaker System Pioneer
Sensitivity 90 dB
Frequency Response 30 - 32k Hz
RMS Power Range (Watts) 2-40
Peak Power Handling (Watts) 120
Design 2-way
Tweeter Design Dome
Tweeter Composition Cloth
Woofer Composition IMPP Rigilite
Woofer Surround Butyl Rubber
Impedance (Ohms) 4
Top-mount Depth (Inches) 2 7/16
Bottom-mount Depth (Inches) N/A
Cutout Diameter or Length (inches) 5
Just a bit of a Pioneer Fan, they sound good and are priced really well as well. Hope I helped, See ya, Brian