To keep the Kicker theme going I would put that sub in a 2.5cu ft ported box tuned to 35 Hertz being run by a Kicker KX mono amp (400.1 for example). If you are not going to see the amps then your options really open up. Then it depends on your budget what I would recommend. And yes, I would use the 4 channel for fronts and rear speakers.
Another thing to remember is that older cars have smaller alternators in most cases compared to now. So I wouldn't go crazy with the size of the amplifier unless you plan on upgrading the electrical which can get expensive.