I'm looking to put a system back in my car. I haven't bought an amp in many years so I could use some help picking out a good one. I will be pushing two polk 12's, can't remember the model though. The first amp is: MTX THUNDER 502 125 watts RMS x 2 at 4 ohms 250 watts RMS x 2 at 2 ohms 500 watts RMS x 1 at 4 ohms bridged Stereo or bridged mono output 4-ohm stable in bridged mode Tri-Way capable Preamp outputs PWM MOSFET switching power supply Intelligent Surface Mount Technology for cleaner sound and greater reliability ThunderEQ Bass Enhancement Variable (40-200 Hz) high-pass/low-pass crossovers 12-5/8"W x 2-¼"H x 9-13/16"D Second amp is: Rockford Fosgate Punch 501S 125 watts RMS x 2 at 4 ohms 250 watts RMS x 2 at 2 ohms 500 watts RMS x 1 at 4 ohms in bridged mode 1500 Watts x 1 at 2 ohms in bridged mode stereo or bridged mono output 4-ohm stable in bridged mode Tri-Way capable requires 8-gauge power and ground leads and a 50-amp fuse — wiring and hardware not included with amplifier continuously variable 50-250 Hz high-pass/low-pass (12 dB/octave) crossovers MOSFET power supply and output devices MEHSA mounting technology increases the heat transfer from the MOSFET output devices to the heat sink, for higher power output, lower operating temperatures, and greater reliability TOPAZ — noise-killing differential inputs that eliminate 80% of ground loop noise Trans•ana circuitry keeps preamp voltages low and signal paths simple for outstanding audio quality NOMAD — advanced protection circuitry for "intelligent" shutdown protection wired remote included for fingertip control of Punch Bass (0-18 dB boost at 45 Hz) speaker- and preamp-level inputs 12-1/16"W x 2-3/8"H x 9-7/8"D Third amp is: Audiobahn A8002T Class A/B MOSFET Circuitry 2 - Channel 2 Ohms Stable Stereo 2 x 200 Watts RMS @ 4 Ohms Stereo 2 x 400 Watts RMS @ 2 Ohms Stereo 800 x 1 Watts RMS @ 4 Ohms Mono (Bridged) Air Intake Cooling Fan 18 dB Bass Boost S/N Ratio: > 100 dB Variable Subsonic Filter: 20 Hz - 50 Hz Variable High Pass Crossover (18 dB): 50 Hz - 750 Hz Variable Low Pass Crossover (18 dB): 50 Hz - 120 Hz Frequency Response: 10 Hz - 40 KHz (+/- 1 dB) THD: 0.02% Cobalt Blue Illumination Mirror Chrome Finish Dimensions (LxWxH): 11 7/8" x 9 7/8" x 1 7/8" Now I've look through the forums and found some people had good experiences with audiobahn others have had bad. Most seem to agree with they are not as powerful ad advertised. I did have good luck with a Rockford I had a while back, although some people here have said they haven't been as good lately. Basically I'm trying to get something good for less then $200 shipped.