You wont get that kind of sound from anything that can mount to the factory rollbar. I have seen the basket rack that mounts a little above the top of the siderails used to hold a radio box. Create a amp/sub/speaker box that is water proof that fits in the basket, the box can be MDF with a layer of glas or kevlar and then bedlined. Run your choice of head unit and it wouldnt hurt to have a set of tweeters mounted to your Apillars.