OK i bought this wiring kit at walmart. it has a 4 ga power lead, then it splits into 2 8 ga powers. I want to run a 500W 4ch amp and a 1000W+ sub amp off of the same power. Would it be ok to use the same power for my ams? or should i run a seperate heavier power direct to the battery? but I dont want to run anymore wires through the car. Would this configuraton be good enough for the power ratings?

Might as well run 0 gauge if you only want to end up running 1.

If the power ratings you gave are peak ratings then you should be fine. if it is RMS you would want 4 gauge going into the amps. So you have to get at least a 2 gauge wire or higher. Also if that is RMS rating I would look into getting a new alt. before anything.

The 4 ch amp is rated at 65 watts rms per channel, so 8 ga should be ok, but the sub amp im looking at is 2000W max, maybe 500 rms. or I might buy a 1000W kenwood. The wiring kit is rated at 1400 watts max.