[Mr.ac]

Besides from internet pics you'll have to do a custom fab job.

Is it a good idea? Not really you really don't gain much room even if you do make it so the back rests fold down. You'll also lose access to the fuel pump if ever need to get in there.

As for sound dampening, you can buy them and install them with out audio equipment and gain noiseless cabin.

I recommend you talk to a custom audio shop maybe they can help you out more than some joe blow from the internet