Best sub system set up for extreme metal?

So I've got a little S10 pickup truck that I'd like to upgrade my sound system on. I'm not looking to piss off my neighbors or anything, but I do like to hear and feel my music.

I've read that 8" speakers will give a much more clear punch then I would expect to get with a larger sub, and that the trade off is lack of earthquake inducing volume. Is that true?

Does anyone have an experience or recommendations with sub systems for death metal, grindcore, speed metal, etc? Should I be focusing more on the mid's and highs? What is a good ratio for subs?

First person with a useful answer, especially with links wins it.

Thank you!