With the Mach 460's and 1000's the head unit only puts out like 5 watts per channel. That's because it's really only a signal for the amp to boost. So your best bet is to find a junked car with the Mach1000 system and buy the amp. I know the Mach460 amps are pretty cheap on Ebay.
C&L 80mm mass air, Mac CAI, BBK 65mm tb, Steeda ud pulleys, MGW shifter, RAM HD clutch and aluminum flywheel, 3:73 gears, 2.5" Dynomax o/r x pipe, 3" MAC cat back system w/ 3 1/2" tips, Kenny Brown(front and rear strut tower brace, caster plates, subframe connectors,extreme matrix brace,jacking rails, torque brace, lowering springs), Tokico D-Spec shocks, 03-04 Cobra(side scoops, rear bumper cover, top), 6pt roll cage, white FR500's, FMS 2000 Cobra R air dam, Steeda race wing, VIS carbon hood.