You didn't give any idea of what your budget is...so, let's go crazy:
Precision Power PCX-480. 80 watts per channel RMS for left and right, 320 mono. Crossovers and all, really decent sounding amp.
Zapco Studio 204. 50 watts per channel, 200 mono...but alas...no crossovers
Zapco Z250C4-SL. 30 watts per channel, 120 mono, crossovers but maybe light on power...I heard one with a basic system that sounded great!
or about a dozen other models from Alpine, Rockford, you-name-it.
1990 Nissan Maxima **SOLD**
Nakamichi Mobile CD Tuner One
Nakamichi CD Changer
Namamichi Digital to Analog Converter
Behringer Ultra-Curve PRO-DSP8024 Equalizer
Audio Control ESP-II
Audio Control Epicenter
Ashley XR-4001 4-way crossover
(2) Zapco Z400C2 Amplifiers
(1 pr) MB Quart Referenz Components
(2) JL Audio 8W1 Mid-bass
(4) JL Audio 10W0 Subwoofers