[D.PASSMORE]

You can still find NOS shaft style cassette radio decks on EBay. You can set them up to play from your phone with assorted small add on equipment. Also, a lot of Amps and speakers on EBay too. If your gas tank is still in cab, there is a few companies or members that sell speaker corners mounts for the rears and you can find the front speaker kick panels enclosures rather easy. This is a lot better than sticking them in your doors. You can mount the amps under the seat, just make sure the air can run across the top and bottom to keep it on the cool side. Also, these cabs have atrocious noise, so ensure you have a good sound barrier to get the most out of your system.