Hey guess what people? HE ALREADY HAS THE AMP! So lay the hell off, everybody has to start somewhere. He'll see for himself how the amplifiers perform and decide for himself if he wants to replace it and with what.
starjammir, it would be a good idea to Augment you ground and engine/chassis ground wires (the big three) to 4 guage along with the new power cable. The stock ground wire is iirc 8 guage or maybe even 10 and becomes a huge bottleneck in your setup. The change should fix most if not all of the dimming light problems.
As for running the main power cable, since you have the ATX, look where the clutch pedal usually is in a manual car. There should be a tear shaped gromet, originally where the clutch cable would pass. Just poke through that. Easy as stealing candy from a dead body.
And BTW, 300W RMS isn't all that bad, I only send my PB15 around 150W RMS from my MRV-T757 (it's all running at 8ohms) and it can move the hair on your head while sounding crystal clear. When My 16Kv.2 gets here, I'll be sending it 300W, that should be fun
