temporary set up would be easy. at least it would help you find out what is wrong. as for a permanent setup, it would not be good since the ground wire would be too long

 

move your ground to somwhere else. the cab is not always a good ground. i would try a bolt on the frame somwhere. as they said above, make sure your power and signal wires are separated, like on opposite sides of the cab. as for your light burning out, how many volts is your alternator putting out? check it with a meter, NOT the factory gauge.

 

I compete in alot of stereo competitions. Lights are dimming because you are drawing more current then what is available. If they are big amps, you will probably need a second battery.

Noise comes from poor grounding and connections. Ground loops will cause noise. If you amps are mounted to the floor board, and you are grounding right there as well, then the RCAs are more then likely to close and causing noise. Like mentioned, make sure to run your signal cables away from your power and ground cables. Most cheap signal cables do not have any insulation. I would relocate your grouns point first and make sure it is secure. Sand down the mounting point for a good ground. Also, check and make sure you did not crimp or bend any cables when you ran them in the truck. This can cause problems as well. Worst comes to worst, get a noise suppresion cap to try and kill the noise.