Hey Cu Bu, that Sony amp sucks first of all and it's only a 2 channel. You can either connect it to the front or rear speakers. If you want to power all of them, then get 4 channel amp. If you HU has rca connectors, use that, if not get speaker level to rca converter.
If that amp is 2 ohm stable you can hook up left (front & rear) to one channel and right (front & rear) to the other channel. Won't be able to fade front to rear, but hey, they will "all be hooked up".
Whoa, well could do that but would it be worth the time and effort?
if the speakers are 2 ohm stable and so is the amp, you could hook up the front left and rear left... in parallel. This, however, would take a lot of speaker wire and wouldnt be optimal. Your best bet if you can spare the cash is to pick up a four channel amp. To hook the speakers in parallel, run a 2 wires from each channel to the rear two speakers, then run another wire from the speakers to the corresponding +/- on the front speakers. Wire left with left and right with right. Make sure the amp and speakers are two ohm stable or you'll be out a few bucks. the speakers probably are not.