S300 down pipe?

[redneckroot]

Ok here is where I'm going/ planning on doing: Finishing up the ladder bars and then taking the rear back out and rebuilding it. Then getting a S300 from a local guy (he bought the bigbaddodge if anyone has seen or heard of it, at the flywheel he layed down 1,400hp so he knows his stuff) grinding the heck out of the fuel pin, playing with the pump, throwing the spring in it (if i can figure out how to) possibily installing the 3 piece manifold, eventually affording injectors big ones. So basically everything but the motor will be rebuilt or new. This truck may end up turning into a pulling truck within the next year or two (mainly because I'm a moron) Does anyone have any other ideas? Oh yeah I bought cool tubz and i'm going to be intercooling it. What I'm held up on right now is trying to price out/figure out an exhaust, what down pipe do i need to run for the s300? I want it to be atleast 4" Should I run a single stack in the bed? or are they to nasty to listen to?